TABL E 0 F CONTENTS

EDITORIAL Diamond Prospecting and Market Prospects Richard T. Liddicoat

FEATURE ARTICLES A History of Diamond Sources in Africa: Part I A. /. A. (Bram)/arise

A Chart for the Separation of Natural and Synthetic Diamonds lames E. Sl~igley,Emmanuel Fritsch, Ilene Reinitz, and Thomas E. Moses

REGULAR FEATURES Gem Trade Lab Notes Gem News Book Reviews Gemological Abstracts Annual Index

ABOUT THE COVER: The modern history of the diamond industry start- ed in the late 1860s, with the discovery of a bright pebble on a farm in South Africa. Soon, prospectors had spread throughout the Kimberley area (and, eventually, into neighboring countries) looking for-and finding- many major alluvial deposits and the host pipes themselves. For more than a hundred years, countries on the African continent dominated the supply of gem diamonds. Even today, they continue to provide millions of carats annually for the consun1er market. The lead article in this issz~e,Part I of a two-part series, provides a fascinating, and factual, history of the diamond discoveries in southern Africa. The 27.74 ct yellow diamond in the pen- dant to this diamond neclzlace is of African origin; ii is surro~~ndedby 19 circular-cut diamonds, which range from 0.90 to 2.53 ct. Necklace by Harry Winston; photo courtesy of Christie's. Color separations for Gems & Gemology are by Effective Graphics, Compton, CA. Printing is by Cadmus Journal Services, Easton, MD. 0 1996 Gemological Institute of America All rights reserved ISSN 0016-626 Editor-in-Chief Editor Editors, Gem Trade Lab Notes Richard T. Liddicoat Alice S. Keller Robert C. Kamnierling 1660 Stewart St. C. W. Fryer Associate Editors Santa Monica, CA 90404 William E. Boyajian Editors, Gem News (310) 829-299 1 x251 Robert C. IZammerling Robert C. Kammerling c-mail: [email protected] D. Vincent Mcinson John I. Koivula John Sinkankas Subscriptions Mary L. Johnson Technical Editor Jin Lim Cristina Chavira Editors, Book Reviews Carol M. Stockton (800)42 1-7250 x201 Susan B. Johnson Fax: (310) 453-4478 Jana E. Miyahira Assistant Editor Irv Dierdorff Contributing Editor Editor, Geinological Abstracts e-mail: [email protected] John I. Koivula C. W. Fryer

Art Director Production Assistant Christine Troianello Gail Young

G. Robert Crowningshiekl C. S. Hurlbut, Jr. A. A. Levinson New York, NY Can~lmdge,MA Calgary, Alberta, Canada Alan T. Collins Alan Jobbins Kurt Nassau London, United Kingdom Caterham, United Kingdom P.0. Lebanon, Nl Dennis Foltz Anthony R. Kampf George Rossman Santa Monica, CA Los Angeles, CA Pasadena, CA Emmanuel Fritsch Robert E. Kane Kenneth Scarratt Nantes, France Helena, MT Bangkok, Thailand C. W. Fryer John I. Koivula Karl Schinetzer Santa Monica, CA Santa Monica, CA Petershausen, Germany Henry A. Hiinni James E. Shigley Basel, Switzerland Santa Monica, CA

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Gems el Gemology wclcomcs the subn~issionof articles on all aspects of the field. Please sec the Suggestions for Authors in the Spring 1995 issue of the journal, or contact the editor for a copy. Letters on articles published in Gems a) Gemology and othcr relevant matters are also welcomc. Abstracting is permitted with credit to the source. Libraries are permitted to photocopy beyond the limits of U.S. copyright law for private use of patrons. Instructors arc permitted to photocopy isolated articles for noncommercial classroom use without fee. Copying of the photographs by any means othcr than traditional photocopying tech- niques (Xerox, etc.) is prohibited without the express permission of the photographer (where listcd) or author of the article in which the photo appears (where no photographer is listed). For other copying, reprint, or republication pcr- mission,. .nlease contact the editor. Gems a) Gemology is puhlislicd quarterly by the Gemological Institute of America, a nonprofit educational organi- zation for the jewelry industry, 1660 Stewart Street, Santa Monica, CA 90404.

Postmastei: Return unilelivcrahle copies of Gems et) Gelnology to 1660 Stcwait Street, Santa Monica, CA 70404, Any opinions expressed in signed articles are understood to bc the opinions of the authors and not of the publishers. Richard T ~iddicoit,Editor-in-Chief -

The search for diamonds has been a preoccupation of wealth-seekers for count- less years. The early discoveries in India, Brazil, and South Africa clearly were fortuitous. More recent discoveries in Africa, as well as on other continents, also have had an element of luck, although many have been based on sound scientific principles. These principles have developed (slowly at first) since the 1870s, when the significance of the kimbcrlite pipes in South Africa was first recog- nized. In the late 1930s) on the basis of these same principles, Professor Vladimir Sobolev discerned the geologic similarities between the diamond-producing areas of South Africa and those of the Yakutia region-leading to the discovery and development of the prolific Siberian diamond mines since the 1950s.

In the two-part article by Dr. Brain Janse, an internationally recognized expert in diamond exploration, the history of diamond discoveries on the entire African continent is discussed. As the "plot" unfolds, one is able to follow the evolution of the discovery and production of diamonds from an increasing number of African countries, as well as the fundan~entalgeologic concepts that now form the basis of all modern exploration programs, but throughout the world.

The success of diamond exploration has been phenomenal, and some have expressed concern over the prospect of a gem diamond glut as production from new sources has become available. The influx of diamonds from Russia (since 1959),Botswana (since the early 1980~)~and Australia (sincethe mid-1980s) has increased the supply at a dramatic pace-since the mid-1980s alone, from less than 50 million to more than 100 million carats annually. Notwithstanding the continual increase in the supply of diamonds over more than a century, there has been no obvious effect on prices, nor on the appeal of diamonds to the buy- ing public (except, possibly, to make them even more appealing!).Demand for diamonds and diamond jewelry, fueled first and foremost by the American mar- ket, subsequently by the ~a~akesemarket (where present demand has been sti- fled by a pervasive recession), and, most recently, by other Pacific Rim countries, continues unabated. Thus, the market would be expected to absorb moderate increases in production from new discoveries without any significant distortion.

Among diainantaires, there seems to be more concern (warranted or not) about the potential impact of jewelry-quality synthetic diamonds, should they ever . become available at a fraction of the price of natural stones. The second article in this issue, and the chart that accompanies it, represent how we at GIA feel that this challenge can best be tackled: through research and education. The well-informed jeweler-gemologist can be just as effective in controlling the impact of synthetic diamonds as the market has been in managing the influx of natural ones. Q

227 Editorial GEMS &. GEMOLOGY Winter 1995 IN AFRICA:PART I

By A. J. A. (Bram) Janse

For more than 100 years, Africa has pro- lthough diamonds have been known for more than duced large commercial quantities of dia- 2,000 years, with the earliest discoveries in India, monds and important individual stones. large-scale mining and distribution date only from The earliest official finds were made from the late 1860s and the first finds in Africa. For almost a centu- approximately 1867 onward, in sands and ry, Africa-and especially South AfricaÑdon~inate diamond gravels of the Orange and Vaal Rivers in production, representing more than 98% of world output South Africa. Subsequently, diamonds from 1889 to 1959. Many of the most famous stones ever to were found in "hard rock" kimberlites and, most recently, in off-shore deposits enter the gem market originated from these African deposits. along the western coast of South Africa In addition, much of our current knowledge about diamond and Namibia. Important discoveries have occurrences, exploration, and mining comes from the African been made in many other African coun- diamond fields. And the history of these discoveries is among tries. Angola, Botswana, Central African the richest in the archives of gemology. Republic, Ghana, Namibia, and Zaire The first reliable records of diamond finds in Africa date have now joined South Africa as being from the late 1860s ("Diamonds are trumps," April 18, 1867). among the top 10 dian~ond-producing These followed the earlier finds in India several centuries B.C. countries worldwide. Part I of this two- (recorded in Arthasastra and Ratnapariska Sanskrit texts, as part series examines the fascinating histo- reported in Legrand, 1984); Borneo in the 10th century A.D. ry of these numerous discoveries in south- (Legrand, 1984); Brazil in the 1720s (Sarmento, 1735; Bruton, ern and central Africa from the 19th cen- tury to the present. Part II will look at 1978*!; Russia in the 1830s (Rose, 1837, pp. 352-374; Webster, eastern and western Africa, as well as the 1975); the United States in the 1840s (Shepard, 1846; Kunz, history of diamond prospecting, n~ining, 1892; Sinlzankas, 1976); and Australia in the 1850s and production on the African continent. (Hargraves, 1851; Atlkson et al., 1990).In most of these earli- er instances, the diamonds were mere mineralogical curiosi- ties, found as occasional by-products in the recovery of gold from sands and gravels in stream beds. Through the ages, pro- duction from India and Borneo reached Europe only as a triclz- le of large (over one carat) stones that were used mainly as adornments for sovereigns and their consorts, with smaller stones used for engraving and cutting tools. The Brazilian deposits provided a steady supply of small stones after 1730 (Lenzen, 1970), but large quantities of stones of significant size (including many 15 ct and above) came only with the exploitation of the South African diamond fields from 1870 onwards (figure 1).In general, this sudden increase in supply coincided with the new wealth generated by the Industrial

228 Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 Figure 1. Africa was the dominant source in the world diamond market for almost a hundred years after the fust pieces of rough were reported in South Africa in the 1860s. This suite of jewelry, designed by Gianmaria Bucceflati, was fashioned born predominantly African rough collected over many years. The dia- monds weigh a total of 344.11 carats. Courtesy of Biiccellati of Beverly Hills, California; photo 0Harold o)Erica Van Pelt.

Revolution and the attendant increased demand for excerpts of original documents) or recollections of luxury goods by a broader range of consumers. people directly involved in the events described. Tills article reviews the history of the major dis- Please keep in mind that the quality of reporting in coveries of alluvial diamonds and lzimberlite pipes 19th-century periodicals is often not as high as in throughout the African continent, from the earliest- recent ones, in that there was less opportunity for on- ill February 1867-near Kimberley, in South Africa, the-spot investigation. As a result, much of the evi- to the most recent discovery-in 1990411 the Sahara dence was based on hearsay. Likewise, personal rec- Desert, in Algeria (figure 2). The stories of the early ollections often contain incorrect information caused diamond discoveries have been told many times, but by wishful thinking and faulty memory. There are many have become distorted and bowdlerized in the several other interesting stories that could have been retelling. As much as possible, the information pro- told, but they were omitted because they could not vided here has been culled from original sources be substantiated. (archival issues of periodicals and photocopies or The following is a country-by-country account

- - - -. .- (basically, from south to north and from east to west) Wherever two references are quoted with widely different of the progression of major diamond discoveries and years, the first reference indicntes the curliest record that I have exploitation in Africa. Part I surveys the important found, whereas the second reference is the more accessible and con~prehensive.Note that they sometimes differ in detail and diamond-producing countries in southern and central interpretation. Africa. Part IT, to be published in an upcoming issue

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 WESTERN SWflA

SEW , a LEW -!*- LW/ -Em 7 - BWffOWAL .a- IK@Y/' SHAW GUINEA , 1 COAST o! A

- figure 2. This map of Africa shows the countries in which diamonds and/or l

230 Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 rock" kin~berlitesources. In fact, South Africa is con- sidered the type locality for the occurrence of dia- monds in igneous host rocks, such as lzimberlite pipes, which were first discovered there in 1869 and recognized as such in 1872. The methods and special equipment now used worldwide for the recovery of diamonds were developed here. Diamond production from lzimberlite pipes around Kimberley exceeded one million carats with- in the first year of exploitation by local miners ("dig- gers"). The largest diamond ever found, the Cullinan (3,106 metric carats), and many other very large dia- Figure 3. The 10.73 ct yellow diamond known as monds were found in South Africa. This country has the Eureka was reportedly faceted from the earliest been a steady producer of several n~illionsof carats recorded diamond in Africa, found in late 1866 or annually up to the present, and important new dis- early 1867 on De Kalk farm near the Orange River. coveries are still being made. Photo courtesy of De Beers. The First Alluvial Diggings. Although a few dia- monds were allegedly found earlier (Balfour, 1992; genuine diamond of 21.3 ct. (It remains unexplained Liddicoat, 1993))the first officially recorded diamond why an experienced diamond cutter, such as Louis on the African continent was found in the southern Hond, would have moved from Holland to Cape henGspherels summer of 186611867, either as early Town before it became known that diamonds were as December 1866 or as late as February 1867 actually found in South Africa. Perhaps the lznowl- (Robertson; 1974*).This stone, which weighed 21.25 edge of earlier diamond finds [see Balfour, 19921 was old carats," was subsequently cut into a 10.73 ct more widespread than has been reported, but this brilliant and named the Eureka (figure3). cannot be substantiated.) The actual location of the This stone was found on a farm named De I

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 Subsequently, Chalmers wrote that OIReilly then went on to Colesberg where the town clerk, Lorenzo Boyes, sent the stone to Dr. Atherstone by letter, dated March 12, 1867 (see Chaliners' letter of January 20, 1969, cited in Robertson, 1974). Atherstone immediately responded that it was a dia- mond of 21.25 ct, worth £500and that he would like to send it to Colonial Secretary Southey in Cape Town (Atherstonc, 1869).** On April 16 or 17, Southey showed the stone to Ernest Heritte, the French consul, and the above-mentioned Louis Hond, both of whom confirmed Atherstone's asser- tions ("Diamonds are trumps," April 18, 1867). On April 19, the stone was sent by a steamer named the Celt to London for final verification by Garrard and Co., the Crown Jewellers. On July 12, 1867, Southey received a copy of the certificate that Garrard had issued the preceding month (June8), which stated that it was a genuine diamond of good quality, slight- ly colored, and weighed 21.16 ct; they confirmed Dr. Figure 4. The first diamonds reporteknd, subse- quently, most of the major mines-in South Atherstone's value of £50 (Garrard's certificate in Africa were located in the area between the Robertson, 1974).A replica of the stone was exhibit- Oraiige and Vaal Rivers. Note thai the. Kimbarley- ed at the Paris Exhibition later in 1867. The diamond area mines are shown here in relative position, not was subsequently purchased for £50 by Sir Philip precise to scale, because they were clustered ill Wodehouse, governor of the Cape Colony. such a small area. Chalmers' story of the find (littlegirl Jacobs, chil- dren playing with pebbles, Van Nielzerk's interest, etc.) was quoted in the influential lecture on the dis- Schallz Van Nielzerlz, when he was visiting in covery of diamonds in South Africa given by February 1867.* He offered to buy it, but Mrs. Jacobs Professor James Tennant at the Society of Arts on scoffed at the idea of selling a mere pebble and gave it November 23, 1870 (Tennant, 1870).Most early writ- to him (Chalmers' account does not say what the lit- ers and, recently, Bruton (1978) follow Tennant's tle girl thought of this). Chalmers states that "Van account. Nielzerk was a very shrewd man with an enquiring In 1872, OIReilly gave a different version of the turn of mind" and credits him with "bringing to light find to Richard Murray, editor of the Diamond Fields the existence of diamonds along the Orange River." Advertiser (publishedin the tent town then called De Van Nielzerlz gave the pebble to a local trader/hunter, Bcers New Rush, later renamed the city of Kimberleyl. John OiRedly, to take it to Hopetown to see if it was OIReilly said that while visiting Van Niekerlz in worth anything, as he thought that it was a diamond. March 1867, he saw Van Nielzerk's little girl playing OIReilly showed it to several people ill Hopetown, with some bright pebbles. He offered to buy a partic- including Chalmers, who all laughed at the idea that ularly shiny one, but Van Niekerlz gave it to him on the pebble might be a diamond. Nevertheless, the understanding that if it was worth something Chalmers says he advised O'Redly to send it to Dr. they would share equally (Murray, 1873).The rest of Atherstone, a physician and self-taught geologist/ the story is as told by Chalmers. - - . - - ,. .- . - -. - - mineralogist living in Grahamstown. * 'The date on the letter from Boyes is reported in A therstone, 1869. Atherstone's reply to Boyes was received in Colesberg on It is strange that Chalmers and Atlierstone described [he April 8. Alherstone determined the specific gravity of the stone, IacobsIVan Niekerk diamond as a white stone. Hond, in his eval- its hardness (it did scratch glass and was not scratched by a atio ion in Capetown, mentioned that it had a small yellow spot hardened steel file), its weight in carats, and its value (probably in one corner ("eengee1 vlekje," h "Eel7 Kciapsche diamant," from the book by leffries, 1750, which includes a manual fir April 30, 1867). Garrard's certificate said "slightly colored" with- establishing the value of a diamond from its weight and dimen- out stating which color (most diamonds from South Africa have sioas). It was a remarkable effort for a self-taught mineralogist a faint yellow hue), whereas the Eureka is distinctly yellow. who had never before evaluated a diamond.

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 In a petition to then-governor of the Cape But how did Van Nielzerlz get that idea? It may Colony Sir Henry Barldy, filed January 10, 1872, at have come from a legend among the Boers that dia- De Beers New Rush, O'Reilly claimed to have found monds were collected by Bushmen along the Orange (or at least recognized) the first diamond identified in and Vaal Rivers (Dunn, 1871).There are also indica- South Africa. Again, he referred to a March 1867 visit tions that Van Niekerlz had found diamonds even to Van Nielzerlz, but in this account (reproduced in before he recognized the Jacobs diamond ("Jacobs' Robertson, 1974, pp. 73-74), he claimed to have diamond . . . ,I' June 4, 1867; "Nelly Jacobs . . . ," July picked out the diamond from among Van Niekerk's 30, 1867).In the mid-1860~~the government land sur- collection of stones. He offered to buy it, but Van veyor, Von Ludwig, often stayed at Van Niekerk's Nielzerk gave it to him, saying it belonged to "Daniel house and the two discussed minerals. When he fin- Jacobs' little Bushman boy." In an 1876 account, it ished his survey of farms along the Orange River, was in the hands of a little Griqua servant boy who Von Ludwig gave Van Niekerlz a boolz 011 gemstones was minding the children (Matthews, 1878).In 1894, (Beet and Terpend, 1917). OIReilly changed the little Griqua boy to a little Regardless of who actually found the first stone, Hottentot boy. In all of these accounts, the rest of the it created a mild stir of interest among the Boers (pas- story is as told above. turalists of mainly Dutch ancestry) and the Griquas O1Reilly's claim that he was the first to recog- (shepherds of mixed Hottentot/Bushman/Bantu nize the pebble's potential was so successful that the ancestry) living in the general area of the Orange and first boolz on the diamond fields (Reunert, 1893),and the most authoritative textbook on gemstones of that era (Bauer, 1896), gave OIReilly the credit "for Figure 5. Erasmus Jacobs has been credited with establishing the occurrence of diamonds in South finding ihe fust officially recorded diamond on the Africa." Both publications called the first stone the African continent, on his family's farm, De IZalk, "O'Reilly Diamond." in 1866. Tills photo was taken around 1907. An account by a nephew of Van Nielzerlz given to Courtesy of De Beers. George Beet in Kimberley states that it was Erasmus Jacobs (figure5)) second so11 of Daniel Jacobs of De Kalk farm, who found the first diamond (Beet and Terpend, 1917).John Noble, who visited De Kalk, also describes the finder as a young son of Daniel Jacobs, and this ver- sion was adopted by Williams (1905).In a sworn affi- davit, dated August 9, 1932, Erasmus Jacobs stated that he picked up a bright pebble near the dam on his father's farm, De Kalk, in the summer of 1866 when he was 15 years old (in Robertson, 1974).A Hottentot was standing by but had nothing to do with the discovery. Erasmus gave the stone to his little sister (Rielzie). When Van Nielzerlz was visiting a month or two later, Erasmus and his brother and two sisters were playing games with some pebbles, including the bright one. Van Nielzerlz acquired it and then passed it on to OIRedy, who took it to Hopetown and Colesberg. This account ties up everything very neatly-too neatly, perhaps. The native servant is there (Hottentot, Griqua, or Bushman), but is dismissed as irrelevant; the little girl is there, but she got the stone from Erasinus; and OIReilly is just the courier. Robertson (1974)commented that the information in the affidavit might have been obtained by "leading questions," that is, by putting words into Erasinus' mouth. Nevertheless, Van Nielzerlz gets the credit for thinlzing that the bright pebble might be a diamond.

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 Vaal Rivers. At least 20 other diamonds turned up frames came into use, and screen sizes went down to during the next two years, found by Griquas and one-sixteenth of an inch (1.6mm, about 0.035 ct). Boers poking around in the gravels of the two rivers Most of the early diamonds were found in the (see Chalmers' "list of 20 diamonds" in Wealzley, Vaal River which, in the area near its confluence 1869; Atherstone, 1869). with the Orange River, flows over amygdaloidal Harry Emanuel, a well-known London jeweler basalt (in fact, andesite). The basalt forms good "trap who had written a textbook on gemstones (1865), sites" for diamonds, with rock bars, potholes, and sent mineralogist James Gregory to South Africa in gravel bars. A party of prospectors from Natal, led by 1868 to check out the discoveries. During his tour a Captain Rolleston, was credited as the first to estab- through the Cape Colony, Gregory did not see any lish that diamonds not only occur lying on the sur- roclzs resembling the nicaceous sandstones and mica face, but also can be recovered by actually digging in schists that had been reported to be the source roclzs the gravel. Their first successful dig was near the for diamonds in Brazil (Claussen, 1841).Consequently, German mission station of Pniel on January 4, 1870 he declared that the discovery was "an imposture, a ("Captain Rolleston's party finds diamonds . . . ,I1 July bubble scheme to drive up land values" (Gregory, 16, 1870; Noble, 1874).* 1868).He said that if there were any diamonds scat- In the early years, then, the South African dia- tered about, they must have been brought there in mond fields did not appear to differ much in charac- the gizzards of ostriches. (Most birds swallow small ter from diamond fields in India, Borneo, or Brazil. stones to help their digestive system; he probably Diamonds were found in alluvial deposits, that is, added the ostriches as an afterthought, because a few unconsolidated sands and gravels located in stream stones as large as several carats were found and beds, flats, and banks, as well as the terraces of rivers. offered for sale while he was in the area.) They were recovered by washing and sieving gravels, Gregory's statements created an uproar in the using picks and shovels and locally made sieves that Cape Colony (Atherstone, 1869). Before the debate were often ingenuously combined to make primitive really took off, though, an 83.5 (old)carat stone (later equipment such as roclcing cradles. The energy was cut into a 47.69 ct pear shape called the Star of South provided by manual labor; horses and mules were Africa; figure 6) was offered for sale by the same Van only used for transport. Nielzerlz who had been associated with the first (Eureka) diamond. This was on March 17, 1869, in The First Dry Diggings. In late 1869 and in 1870, Hopetown (L. Hond letter cited ill Wealzley, 1869). however, diamonds were also found in places that Van Nielzerlz got the stone from a Griqua shepherd were nowhere near an obvious watercourse. They named Swartbooi, who said that he had found it on were recovered from reddish loamy surface sand and the Sandfontein farm, which was also near the con- from yellowish friable calcareous dry mud underlying vergence of the Orange and Vaal Rivers. Van Nielzerlz the red sand. The yellowground was later found to gave Swartbooi all he possessed: 500 sheep, 10 head overlie harder, compact, bluish gray roclz-blue- of cattle, and one horse (F. Steytler letter dated March ground-which eventually was called kimberlite. 18, 1869, cited in Robertson, 1974, pp. 173-174). Van Because they were far removed from any obvious Nielzerlz then sold the stone to Lilienfeld Brothers, streams or rivers and lacked water during the sum- general merchants in Hopetown, for £1,200. mer season, people referred to them as "dry" diggings This event removed all doubts in the minds of in contrast to the alluvial "river" or "wet" diggings. most people in southern Africa, many of whom soon Most lay accounts of the history of the South took to searching the sands and gravels of the Orange African diamond fields (see, e.g., Dickinson, 1965) and Vaal Rivers. Because these early diggers knew lit- state that the Koffiefontein and the Jagersfontein tle about alluvial mining, the earliest efforts were were the first lzimberlite pipes discovered, but early inefficient, recovering only diamonds of one carat correspondence reveals that diamonds were recov- and larger. Hubner (1871)wrote that in 1870 the ear- liest sieves were made of pieces of corrugated iron -. .- . -- - - - Ill-house records of the Pniel Mission note the local find of a sheeting that had been pierced by nails to make diamond in 1859. Dunn (1871)mentioned the existence of an holes, so the smallest sieve size was one fifth of an 18th-century missionary's map that has the words "here be dia- inch (5 n~in).Consequently, only rough stones over monds" covering part of the Orange and Vaal River areas. Maps of this kind are not rare. The author has seen replicas of "mis- one carat (about 5 mm in longest dimension) were sionciry maps" with the words "here be diamonds" in Dutch or retained. A year later, metal screens in wooden Spanish for various parts of the world.

234 Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 ered first from the pipes at Dutoitspan and Bultfontein. In July 1870, the foreman of the Jagers- fontein farm, a man called De IUerlz, found a 50 ct diamond in a small dry creek on that property (Steytler, 18701.1have not found any early records on Koffiefontein. However, Beet (1931) states that the first diamond was found there by a transport rider (the equivalent of today's long-distance truck driver) named Banl, also in July 1870. Both finds were made in small tributaries of the Riet (Reed)River and were first considered river diggings. Yet, in a paper deliv- ered before the Geological Association in London in December 1872 (Paterson, 1873)) the statement is made that the Jagersfontein and Koffiefontein worlz- ings do not represent alluvial diggings, but rather they are similar to the Dutoitspan diggings, which by that time were already regarded as being other than river diggings. In fact, in a letter dated November 4, 1869, Fred Steytler wrote that during a visit to Dutoitspan farm the preceding month, he saw hundreds of garnets and some diamonds in limy soil (Robertson, 1974, p. 219). Not only is this several months before the first report of diamonds at Jagersfontein and Koffiefontein, but Figure 6. The 1869 discovery of the large dia- Steytler's association of red garnets and diamonds mond from which this 47.69 ct pear shape known as the Star of South Africa was cut sent suggests that early prospectors had an inkling that many people to the Orange and Vaal Rivers to the occurrence of garnets was in some way related to start digging for diamonds. Photo courtesy of the the occurrence of diamonds. Central Selling Organisation. Draper (1905)stated that the first diamonds not associated with a watercourse were actually found on Bultfontein farm sometime before November 1869. pebbles (which he had recognized as diamonds) from He claimed that he was present in a small store on Mrs. Van Wyk at Dutoitspan (Murray, 1873). the Vaal River on November 6, 1869, when Cornelius Duplooy walked in and showed him a few Discovery of the De Beers and Kimberley (the Big diamonds that he had found in the mud with which Hole) Pipes. These first two dry diggings (Bultfontein he built his house at Bultfontein. The mud came and Dutoitspan; Jagersfontein and Koffiefontein were from the edge of a large pan (i.e., a large shallow still considered wet diggings in 1870)did not generate depression) named Du Toit's Pan about 25 kin (16 much interest, both because the diamonds were miles) east of the Vaal River diggings. Further excava- small (Higson, 1870) and because living and digging tions revealed more diamonds in the small quarry conditions were not very pleasant on the hot, dry and also at a spot 500 in further north along the edge plains. Most would-be miners left for the Vaal River of the pan, on the neighboring farm owned by in January 1870. Summer was at its height, the water Adriaan van Wylz (called Dorstfontein, but once part had run out (Babe, 18721, and they had heard of the of the original Dutoitspan farm). These two mud Rolleston party's success in finding diamonds at quarries became the two famous diamond pipe Pniel. In May 1871, Richard Jackson and party left mines, Bultfontein and Dutoitspan (figure 7). the river diggings to check out a rumor and found a Another account states that the diggings on lone Boer named Corneilsa (probably Cornelissen, a Bultfontein started in September 1869 (report by F. S. common surname in Dutch) digging for diamonds in Philipson-Stow, cited in Robertson, 1974, p. 221). a depression on a farm adjoining Bultfontein and However, J. B. Robinson, a well-known early digger Dorstfontein (Dutoitspan)to the west. This farm- and diamond buyer, claimed that on his first trip to insightfully named Vooruitzigt ("Foresight," or the Vaal River at the end of 1868, he purchased some "Expectation")-belonged to two brothers, Johannes

Diamond Sources in Africa: Part I GEMS & CEMOLOCY Winter 1995 235 Nilzolaas and Diederilz Arnoldus De Beer. Because Gilfflan's Kop a week or two before Danion was told the diamonds at this dry digging were plentiful and to dig there (this story is first told in Beet, 1931). relatively large, the place was soon overrun by min- Gilfillfln's Kop was probably the only place for 11des ers in what came to be known as the De Beers Rush around De Beers Rush to have trees and shade for a pic- (Williams, 1905). nic, as depicted in a Mary Barber watercolor that is now Two months later, in mid-July 1871, diamonds in the Ihnberley mine museum. This diamond stayed were found at the foot of a low hill formed of porous in die Ortlepp family until recently, when it was placed calcareous rock, Gilf illan's Kop, which was 3.5 km (2 on permanent loan at the Africana Museum in miles) west of the De Beers Rush. Tills marked the Johannesburg (J. Hummel, pers. coinm., 1995). start of the De Beers New Rush and became the Big A large tent settlement grew up between Old De Hole (later the Kimberley mine). The credit for tills Beers and De Beers New Rush. On July 5, 1873, this discovery is usually given to the Rawstome party, settlement became the town of Kimberley. These originally from Colesberg, who were digging at the two dry diggings, together with Bultfontein and original (later "Old") De Beers Rush. One night when Dutoitspan, fit within a circle 3.5 lzm across. They the party's cook Damon was drunk and boisterous, developed into the four famous diamond mines locat- the other men sought to get rid of him by telling him ed on kiniberlite pipes in and around the town of to go and dig "on that hill over there." He did, and Ihmberley: the Kimberley (the Big Hole), De Beers, found a diamond. The hill was proclaimed a public Bultfontein, and Dutoitspan mines (again, see figure digging on July 21, 1871. It was subsequently 4). From the earliest days, they produced some spec- renamed Colesberg Kopje (Williams, 1905). tacular stones (figures 8 and 9). However, Sarah Ortlepp, wife of an Orange Free The dry diggings quickly became far more impor- State surveyor, claimed to have found the first stone by tant than the river diggings. Not only did they con- accident while picnicking in the shade of a tree on tain more diamonds per volume of ground being dug

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 surface [see, e.g., figure 11), with mules used to pro- vide the power. Water caused further problems; to pump it out, steam engines made their first appear- ance in 1875 [Williams, 1905).By 1878, fallen reef (the non-diamond-bearing rock that forms a wall around the pipe) became a very serious problem and cost much money to remove. To raise the necessary capital for mechanization of the mining operation and removal of the fallen reef, the smaller claims were consolidated into major new companies. By 1883, all of the diggings at the Kimberley mine were controlled by a few companies. The most important of these were the Kimberley Central Diamond Mining Company (controlled by Barnato Brothers) and the "French Company" (actually the Compagrue Franpise des Mines de Diamant d~iCap de Bonne Espkrance), which was run by the Rothschild family in Paris. By the end of 1882, the excavations were 120 Figure 8. The 55 ct Porter Rhodes diamond (named nl (400 feet) deep and underground mining had start- for the man on whose IZimberley mine claim it was found) was cut from a 154 ct stone considered to be the finest African diamond found up to 1880 Figwe 9. One of the most famous stones found at (Krashes, 1993). Photo courtesy of Harry Winston Inc. Dutoitspan is this 253.70 ct well-formed crystal known as the Oppenheimer diamond, which was recovered in 1964. Courtesy of the Sniithsonian Institution. up, but the fine-grained dry yellowground was n~~ich easier to process than the gravels. (Hard "blue- ground" had not yet been encountered.) Although as many as 20 other lumberlite pipes were found around Kimberley over the next 20 years, not until September 1890 was another economically successful lumberlite found-no more than 8 kin (5 miles) from the Kiinberley town center [Williams, 1905). First called the Premier, the name was changed to Wesselton when a larger pipe found in Transvaal in 1903 was also called the Premier.

Consolidation of Claims. In the early days of the dry diggings, individual miners were allowed to register one claim of 31 x 31 feet square. After 1872, when the pits on some claims became deeper than those on adjoining claims, and passageways between them started to fall in (figure lo), two claims were allowed to combine; in 1874, blocks of 10 claims were per- mitted. Eventually, the fnable yeLlowground ran out and gave way to hard, compact bluegro~ind,which was more difficult to work. Gradually, syndicates and small companies bought out the individual min- ers (Reunert, 1893). Around 1874, the open pits in the Kimberley mine had reached such depths (about 30-40 in) that mechanization was essential to haul the ore to the

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 23 7 ed; by 1884, almost all ore at Kimberley came from was considered the world center for economic lum- underground workings (Reunert, 1893). berlite pipe mines (C. Rhodes, quoted in De Beers The De Beers mine was 100 m deep in 1882 and Annual Report, 1896). The discovery of the first was experiencing the same problems as at Kimberley. Premier (later called Wesselton) pipe in September hi 1880, Cecil Rhodes and his partners formed the De 1890, less than 8 lzm from Kin~berley,seemed to con- Beers Mmh~gCompany and began to consolidate all firm this view. Eventually, all five econon~icpipes claims on this pipe into a single entity. De Beers around Kimberley, plus the Jagersfontein and Mining's first technical manager was American min- Koffiefontein pipes in the Orange Free State, were ing engineer Gardner F. Williams, who had been either owned, leased, or gradually purchased by De manager of an alluvial gold mine near Oroville, Beers Consolidated Mines, which controlled tlie out- California, that had also produced a few hundred put of all economic diamond pipes in South Africa by small diamonds (K~inz,1885)! Williams (1886)wrote the turn of the century. (The purchase of all shares in the first detailed paper on the technical aspects of Koffiefontein was con~pletedin 1911.) operating tlie De Beers mine, which by 1884 had started underground workings. By 1887, all claim Discovery of the Premier Pipe. The Kiniberley area's blocks in the De Beers pipe had been bought up by dominance of diamond production in South Africa De Beers Mining. In the Kiinberley pipe, Rhodes's De changed in 1903 when the large Premier pipe was dis- Beers company first purchased the "French covered 30 kin east of Pretoria, the capital of the Company" and then, in 1888, bought out Barnato Transvaal-500 lun northeast of Kimberley. Alluvial Brothers' "Kimberley Central" to form De Beers diamonds and a few small pipes had been found in the Consolidated Mines (Williams, 1905). By 1889, De general area as early as April 1897 (Molengraaff, 1897)' Beers had completed leasing arrangements for the but the Boer War (1899-1902) halted prospecting Dutoitspan and Bultfontein pipes. activities. By 1898, Thomas Cullinan, a builder and local brick manufacturer from Pretoria, had recog- Kiinberley-the World's Center for Economic nized that alluvial diamonds found on the Diamond Pipes. As the 19th century drew to a close, Bijenestpoort (Beehive Pass) farm came from the many other kiinberlite pipes were discovered in South adjoining farm to the east, Elandsfontein, A diamond Africa, but they either were not diamondiferous or was actually found right beneath the wires of were low in grade or small in volume. Furthermore, it Ehindsfontein's western fence (Heline, 1974). appeared that the closer the pipes were to Kimberley, Elandsfontein's owner, Prinsloo, would not sell and the bigger and better they were. Therefore, Kimberley threatened to shoot any diamond prospectors tres- passing on Ills farm. Nevertheless, in November 1902, after Prinsloo's death and the end of the Boer War, Figure 10. By 1872, as this early photo shows, the Cullinan was able to purchase the farm from walls between pits at the ~

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 199.5 vaal) Diamond Mining Company (Liddicoat, 1993; figure 12). Not until 1920 did the Premier's board of directors reach an understanding with De Beers on levels of production. In 1922, De Beers finally acquired all shares in the Premier mine ("De Beers issuing . . . ," 1923, p. 70). The Elandsfontein area continued to produce many important alluvial dia- monds, including the 726 ct Jonker and 287 ct Pohl diamonds, both found hi 1934.

Underground Mining. The Itimberley and De Beers mines became the first underground diamond-rnin- ing operations in 1882 and 1884, respectively, when workings reached depths of 120 m (400 feet). By the time the Kimberley mine was closed in 1914, it had been worked down to 1,098 m. The De Beers mine was closed in 1908; it was re-opened in 1963 as a modern underground mine, and was closed again in November 1990, when workings had reached 720 nl (De Beers Annzzal Report, 1990).A gradual transition from open-pit to underground mining took place in Figwe 11. As the 1~1iningclaims in the Kimberley the other three diamond pipe mines around area consolidated and pits got deeper, n~echaniza- tion was needed to bring the miners to the ore and Kin~berley-Bultfontein, Dutoitspan, and Wesselton transport the ore to the surface. Photo from (figure13) from 1906 to 1910, when depths from 120 Williams, 1905. to 150 in were reached. The Jagersfontein mine was worked both open pit and underground until 1932, and then again as an widenings of a fissure), were known in the Orange underground mine from 1949 until 1971. The Free State (Molengraaff, 1895) and in the Cape west Koffiefontein mine remained open pit until its clo- of Kimberley. From 1905 on, intermittent mining sure in 1931. It was re-opened as an open-pit mine in took place at Driekoppies (New Thor, Phoenix) and 1971, converted to an underground mine in 1977, Roberts Victor, New Eland, and Monastery (a small closed again in 1982, and re-opened in 1988; it is std pipe) in the Orange Free State, as well as at Frank active today (De Beers Annual Reports, 1971 to pre- Smith-Weltevreden, Sover-Mitjeniansluaal, Newlands, sent). The Premier mine (figure 14) closed in 1932, and Leicester (a small pipe) in the Cape. All these was re-opened as an underground mine in 1946, and mines were closed temporarily during the periods is still active. It is the source of many superb stones, 19 14115, 1921/22, 1932134, and 1940144 (see "History including the 426.50 carat piece of rough from which of Diamond Production," in Part JI) and for several the 128.25 ct D-flawless Niarchos was cut as well as periods during more recent times when demand for the 599 ct rough that produced the 273.85 ct D-inter- new mine production decreased. nally flawless Centenary diamond (figure 15). The In 1958, high-grade, good-quality fissures were Finsch mine started as an open-pit operation in 1966 found at Bellsbank/Bobbejaan, 80 lan northwest of and was converted to underground mining Kimberley. These have been successfully mined September 1990, after the pit reached a depth of 430 intermittently since then (figure 16). During the last nl (De Beers Annual Reports, 1 966 and 1990). decade, most of the fissure mines and small pipes Currently, the only operating underground &a- have been re-opened, with a combined (non-DeBeers) mend mines are in South Africa. All other diamond production that the author has calculated to be as pipe mines worldwide are open pit. high as 200,000 carats per year. Most of these are underground mines. Fissure Mines. As early as 1895, narrow fissures (actually dikes, but called fissures in South Africa)- The Lichtenburg Gravels. From the 1880s on, alluvial 50 cm to a few meters wide and several kilometers diamonds were found farther and farther upstream long-and related small pipes or "blows" (local from die original Vaal River diggings (Coe, 1904). By

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 Fig~i~c12, This 11ec1&1ce, which has a 2.60 ct b1~1e diamond as its center stone, was (1 present from Premier mine Chairman Thomas C~~lfih~~nto 171s wiie, Annie, in celebra- tion of the gift o{ the CtzUinon dio~nondto King Edward VII of England in 1902. Co~~rtesyof S. H. Silver. Photo 0Harold d Erica Van Pelt

the ~LWIof the centuryl diggers had reached Bloemhof watercourses to connect them. Some people believe (again)see &re 4).During 1907-191 1) diamonds were that there is a lumberlite pipe beneath each hole (B. cliscovered in a thin layer of gravels well away from Von Gottberg) pers, comm.l 1982))but the consensus the northern bank of the river! on Mooifontein fcmn is that the holes are the remains of an old river sys- (Harger! 1911). In 1922) diamonds were found in gav- tein since eroded (seele.g.! Wilbamsl 1930). els on Sterldontein farm in the headwaters of the Mooi Each dia~nonddeposit on the plateau was River! a northern tributary of the Vaal ("The thrown open to the public by an organized llrush.J1A Sterkfontein diamond dqgmgs1" 1923). Transvaal governinent official stood on a cart and Thenl in February 1926) the first dian~ondswere read a proclamation declaring a farm! or part of itl found near Lichtenburg on the high) flat plateau that open for dilimestone plateau. Filled with red sandy by Gardner Willian~s'sson) A. F. Williams (l93OjI soil and coarse liver gravelsl the holes had no obvio~is who was general manager of De Beers Consolidated

Diamond Sot~rcesin Africa: Part 1 Winter 1995 Mmes from 1904 to 1931. At the height of mining! in Ronaldson and J. van Praagh! who had bought the 1927) the gravels prod~lced2 million carats of dia- property/ invited the Consolid;~tedAfrican Selection monds. Although activity has dropped off drainatical- Trust (CAST)la diamond mining coinpany in the lyl the field is still worlzed sporadically, Gold Coast (now Ghana) to evaluate the deposit. CAST'S prospectorsl George and Ronald Derinodyl Namaqualand Coast. Diainonds were discovered in two brothers originally froin Ireland! submitted a coastal deposits/ actually dune valleys! near Luderitz favorable report (SelectionTrust in-house reports]. To in South West Africa (now Namibia) in April 1908 develop these deposits! the Cape Coast Exploration (figure 17; see below). In August 1925/ anlateur Company was incorporated in January 1928. CAST prospector Jaclz Carstens found the first dainond on originally obtained nearly a third of the shares! but the coast south of the Orange River! in South Africa! Anglo American and Barnato Brothers had bought near Port Nolloth (Reuning1 192gj Carstens! 1962). out everyone by January 1939 (Greenhalgh, 1985). The area was soon overrun by amateur prospectors as Systematic minmg started in 1929! was suspended in well as some professional geologistsl SLIC~Ias Hans 1932/ and res~unedi111937. The IUeinzee deposit was Merenslzy and Ernst Re~ining. inined out in 1958! hut adjoining deposits to the Merenslzy was famous for discovering the plat- north at Tweepad :1i1c1 Dreyerspan and to the south at in~~in-bearinghorizon that bears 111s name Annex IUeinzee are still being worlzed. (llMerei~slzyReef1') in Transvaal Province (Lehnlan! The Precious Stones Bill was rescinded in 1960. 1955]/ and Re~ii~inghad n111ch experience with the By then! Dc Beers had purchased allnost all the farms coastal diamond deposits in South West Africa. In (and their mineral rights) along the Namaqualand Januaiy 1927) Merei~slzydiscovered the "oyster he1! coast from near Port Nolloth south to the mouth of in the Alexander Bay region. He found that the dia- the Olifants River! a distance of 320 la(200 miles). inonds in this area are associated with a raised beach These areas were n~appedand prospccted in 19.58 and terrace (a terrace fonned when sea level was ligher 1959 (the author participated in these surveys as his than at present)! which also contained many oyster first job)/ and in the early 1960s several minable shells (Wagner and Merenslzyl 1928).He pegged his rescrves were outlined along the coast at Kohg~aas now-famous oyster line and formed the H. M. and Hondeklip Bay. Mmhg started at 1Coingnaas in Syndicate. 1978 ("Kougnaas alluvial diamond inine , . . 1978) The sudden increase in diamond production due and is still ongoing. De Beers and Transhex are to the Lichtenburg discoveriest combined with the ricl~nessof the Nainaqualand coastal depositsl caused the South African government to pass the Figure 13. Once cleptlis of 120-150 m were reached, Precio~isStones Bill in Novenlbcr 1927-forbidchng lninuig mnzpo~iiesat pipes Hie the Wesselton (sl~own f~irtl~erprospecting and digging for diamonds on here) had to go unclergrozzl~cl. state-owned land in Cape Province (K~inz!1929). However! the H. M. Syndicate was awarded its dis- coveiy claims (a prospector who fhds a new pipe or alluvial deposit is awarded two claims)! and inining started h 1928. The remainder of the oyster line was talzen over by the South Afric'm government and pro- claimed the Alexander Bay State Alluvial Diggngs ("Government intends . . . /I1 1928).In 1930, the State Alluvial Diggings acquired all the cliscovery claims in the area! including those of the H. M. Syndicate. They were partly privatized in 1989 into the new Alexander Bay Development Corp. ('lAlexcorll)l whch has since been granted three sea concessions. Other important diamond deposits were discov- ered in 1926 at the mouth of the Buffels River at IUehee. They were also exempt from the prohibi- tions of the Precious Stones Billl because the area was a freehold property, Johannesburg jewelers G. S.

Diamond SOLI~CCSin Africa: Part I GEMS & GEMOLOGY Wintcr 1995 presently mining at Hondelzlip Bay. Minable reserves er diamonds from submerged beaches in tidal zone A! were also located at Langhoogte in 'ancient river ter- operating from the shore. Divers supported by long air races along the Buffels kverI the largest of the dry river hoses guide powerful suction devices that transport beds that are common along the Namaqualand coast. gravel and sand to the beach where they are washed Mmmg started there in 1978 and is still ongoing. and sorted. III zone B (shallow sea)! sinall boats are In 1966/ Baxter Brown and Hugh Jenner-Clarlze also usedl but such operatio~lsfrequently have to be were the first to discover ahvial diamond deposits in s~~spendedbecause of rough seas (G~irneyet al.! 19911. fossilized channels (earlier coLirsesl bends! or mean- ders that are now covered by terrace sands and gav- Discovexy of the Fhsch pipe. In 1963! De Beers pur- els of the present river bed) in the lower course of the chased a large pipe prospect from Alastair Fincham Orange River's south banlz (Wilsoi~~1972). These 'and Wilheh Schwabell who named their find Finsch deposits became the Ochta mine and Baken after the first three letters of their surnames. Beca~~se Dia~nante~which prod~icedlarge! good-qi~ality of the 1927 Precious Stones Billl the prospect was stones. Other fossilized channels have since been first pegged as an asbestos claim in 1958. When this fo~indon the north ball<. law was repealed in 19601 the prospectors started to worlz their claiin for diamonds and offered it to De Off-Shore Deposits. Texas oil Inan Sam Collins Beers. The latter deched the offer on the advice of forlneci the So~ithemDiainond Corporation in 1961 one of their geologistsl who had gotten uneconon~ic to prospect for and eventually mine diamonds from results from a bullz sample collected i11 one large deep the sea floor off the coast of Nainaq~al~md.De Beers pit. The prospectors then dug a long! shallow trench toolz over management of Southern Dia~nondin right across the pipe and found patches of high-grade 1964. Altho~~ghprospecting and research have con- lumberlite (a~ithor'sown files). De Beers later agreed tinued! there has as yet been no systematic mining to pay 4.5 mikon Rand (about US$4 nlillion) to pur- operation. chase this 17.9 ha (44 acre) pipe ("Finsch Diamonds The South African govemnleilt has dvided the (MY]Ltd. acq~liredby De Beersl'' 1963).Finscl~ came sea concessions into 14 blocksl further subdivided into production in 1966 and was officially opened into zones A [tidal)! B [sl~allow)~and C (deep as Febriiary 27! 1967. It soon produced 3 million carats dustrated in Gurney et al. (1991). Several junior min- per year. Finsch became an underground mine in ing coinpanies (notably Benguela Concessions) recov- September 1990)when a depth of 430 m was reached (figure 18).

Figure 14. The Premier mine, 11ere s110wn in (7n Discovery of the Venetia Pil~e.Altho~gh one wo~dd early-2Gth-cent~~ryphoto, was mined open pit ~~ntil thinlz that South Africa had been thoroughly it closed in 1936. Reopened iti 1946 0s an ~~nder- prospected over the years! a wholc new field of dia- ~OLLII~mining operaiio~~,it is stg being actively mondiferous kimberlites was recently discovered in worked. Pl~otocouItesy of De Beers. the northern Transvaal. In the mid-1970~~while prospecting for copper on the Venetia farml Saturn Mining (a s~lbsidiaryof the hglo Vaal group] and African Selection Tmst intersected a sinall luinber- lite fiss~lrein one drill hole (Selection Tmst in-house reports). De Beers acquired a lease from Saturn Mining to prospect for ki~nberlites~and in 197911980 De Beers geologists fo~lnd12 pipes. The Venetia nline1 on the largest of the pipes (12.7 ha (31 acre])! started production in 1991 and was officially opened August 14! 1992. It reached its planned production of 5 million carats per year in 1993! and is scheduled to produce this amount annually for the next 20 years.

Future Prospects. The discovery of the Venetia pipel which came more than 100 years after the original lmlzilnberlite discoveries around Ki~nberley~showed

242 Di:~monclSo~~rces in Africa: Pgrt I GEMS & GEMOLOGY Winter 1995 that newJ iinportant, ecoi~oinicpipes can still be found in South Africa. Diamondiferous fissures may still await discovery in the central part of the Orange Free State! the eastern and western Transvaal! and the northern Cape areas. It is also possible that a large pipel covered by soil or calcrete! could be found in an area that is difficult to prospect. Th~is)althougl~ the co~mtryhas been prospected for a long tiinel there is still hope for new economic discoveries. LESOTHO (Formerly Basutoland) The first concession to prospect for diamonds in Basutoland (now Lesotl~o)was granted by the Basuto parainount chieftainess to Colonel Jaclz Scott in 1954 ("Colonel Jaclz Scott . . . 1978).Several lzimberlite occurrences were described in the first official report on the geology of Basutoland (Stoclzleyl 1947))b~it it was specifically stated that none had yet been found to contain diamonds. Figzzre 15. Many superb diamonds have rece~ztly come fron~the Pren~iermine, incl~~clingthe 599 ct In 19591 De Beers geologists joined Jaclz Scott's dia1710ndfro171 whic11 this 273,85 ct D-color (inter- prospectors aid two post-graduate st~~dents,Barry naLly fl~~wless)Ce~~ten~lty di~~lnond was c~lt.Photo Dawson and Peter NixonJ from the newly formed co~zrtesyof De ~ee~i. Researcll Institute for African Geology at the University of Leeds! England! where the first modern research on lzimberlites was started (Dawsoi~~1962; too smdl to sustain a substai~tialinining operation. Nixon et al.! 1963). De Beers withdrew in 1962! and However! in 1983 Transhex started a mine that is the Iocean-floor deposits. ed at 31000 m altitude in the Dralzensberg Mountains. When mining started in 1977 011 a 3.7 ha First Discoveries in 1908.11e first all~lvialdian~onds (9 acre) section! Letseng became the highest diamond were fo~lndin April 1908 by railway worlzer mine in the world ("Lengthy wait . . . 1978). The Zacharias Lewala! near I

Diamond Sources in Africa: Part I GEMS & GEIMOLOGY Wintcr 1995 ume (Wagner) 1914). S~~rfacemining continued ~intil Oranjemund. CDM headquarters moved froni World War I intervened. In 1915! the country was Ludentz to the new township of Oranjeiiiund (Orange occ~lpiedby Soutli Africa and ownership of the mines mouth = 1110~1thof the Orange River) in 1943. In this was transferred to the Custodiai~of Eneiny Property. area! diaiiionds are found in sands and gravels of ancient 1ii:irine terraces. These occur up to 35 m Birth of CDM in 1919. After the war! Consolidated above present sea level and are covered by an overbw- Diamond Mines of South West Africa (CDM! created den of dune and beach sand as IIILIC~as 12-15 m thiclz specifically for this purpose by Emest Oppenheinier) (Hallainl 1964; M~lrrayet al.! 1970J.H~ige eaitli-inov- toolz overl reorganized! and purchased the properties of ing machinery is used to reinove the overb~lrden. the various Gerinan companies. (In 1917) Oppeiilieiiner had formed the Anglo American Offshore and Foreshore Mining. In the early 1960s) Corporation of So~itl~Africa [AAC] to raise venture the idea emerged that dianionds would also be foud capital for investment in the Witwatersrand gold in s~lb~nergedinarine terraces farther out to sea. hi iikes; AAC tmlz a large shareliolder position in CDM 19611 Sain Collins formed Marine Dian~ond in 1920.)Mining of the I~olmcmslzopaid Elizabeth Bay Corporation ("Diainonds mined off the seabedt'! areas res~imedthro~igli the 1920s and 1930~~but in 1962) and obtained a sea-mining concession. Maiine 1928 diamondifero~isniarine terraces (raised beaches) Diamond worlzed the sea floor near the coast froin were fo~~iidin the areas north of the ino~~tliof the October 1961 to J~lly1963! producing SllOOO carats. Orange River ("Another great diamond disco~ery~!~ However! ~lnpredictableweatlier) ro~igliseasl inade- 1928; I

Submarine Mining. Mter several years of research and prospecting actual sea-bed inining operations started in 1991 in Namibian waters as deep as 100 m, Altho~ighfirst-year prod~lctionwas modest-about 1251000 carats-by 1994 diainond prod~lctionfroin submarine deposits already accounted for 3 1% of Naniibials total prod~lction(De Beers Annual Reports for 1991 to 1994). These deposits are believed to extend to the edge of the coiitinental shelf (upto 100 lun froin the shore) in water over 100 m deep! so mining costs will be hgh. However! the quality of the diainonds recov-

GEMS & GEMOLOGY Winter 1995 ered is exceptionally good and the deposits are huge (Gurney et al., 1991; Meyer, 1991).

New Mines. CDM has also opened two new mines on land in recent years: Elizabeth Bay, on the coast, 30 knl south of Luderitz; and Auchas, on the north bank of the Orange River, 45 km inland. Elizabeth Bay's ore reserves have been calculated at 38 million tonnes at 6.6 carats per 100 tonnes, that is, more than 2.5 million carats of good-quality small stones (Boting and Russel, 1993).The mine, started in June 1991, is projected to produce 250,000 carats annually Oaf, for 10 years. Alexander> Reserves at the Auchas mine are 12.3 million b Bay tonnes of ore (under 45 million tonnes of sandy over- burden), with 3.6 carats of diamond per 100 tonnes (Croll and Cooper, 1993). Plans are for the mine, started in July 1990, to produce 45,000 carats of good- quality, larger-than-average diamonds annually for 10 years.

CDM Becomes Namdeb. After intense negotiations, CDM was restructured in November 1994 as a new company, Naindeb Diamond Corporation. (Namdeb), Figure 17. This map shows the key areas where dia- owned in equal shares by De Beers Centenary and the monds are being mined in on-shore and off-shore Namibian government (see, e.g., "Namibia: The gov- deposits along ihe coasts of Namuquc;la11d(in South ernment is . . . ," 1995, and "Namibia: De Beers . . . ,'I Africa) and Namibia. The broken line above the 1995). Orange River in Namibia represents the outer bound- ary of the restricted diamond area. The inset shows the Kimberlites. The first kimberlite in Namibia was dis- outline of Namibia. covered at Gibeon Village in 1889. By 1906, several other occurrences had been identified as far as 50 lzm east of Gibeon, near Mukorob, and 85 km south of Gibeon, near Brukkaros (Scheibe, 1906). The site Early Discoveries. Although earlier finds of alluvial "near Bnilzkaros" where a 2.75 (old)ct diamond was diamonds had been rumored (Wayland, 1949), the allegedly found in 1893 could not be confirmed, and first officially recorded discoveiy~ofthree small &a- the lhberlites in the Gibeon field proved to be bar- mends (0.27, 0.14, and 0.02 ct)-was made in the ren (Janse, 1975). Namibia has at least four other Motloutse River near Foley in 1959, by a prospecting kimberlite fields, but all proved to be barren. party led by Humphrey Willis of CAST/Selection Trust (Boococlz, 1960, 1965).The diamonds could not BOTSWANA be traced to a host kimberlite; rather, they were (Formerly Bechuanaland) believed to come from an intermediate host, a con- Botswana is the second largest diamond producer by glomerate of the Ecca series (SelectionTrust in-house volume on the African continent, and the largest pro- report), and the company allowed their lease to lapse. ducer by total value in the world. Diamonds are recovered from two of the largest-laown lumberlite Discovery of Orapa. Most of central Botswana is cov- pipes-Orapa and Jwaneng-and one small one, ered by the Kalahari Desert, a vast expanse of red Letlhakane (figure 20). There is no production from sand dunes that lie in long rows separated by valleys alluvial sources. These lumberlite pipes were discov- covered in grass, bushes, and clumps of thorn trees, ered only relatively recently, because a large part of but no surface water. The De Beers subsidiary the country is covered by a thick layer of desert sand. Kimberlite Searches started prospecting in 1955 in

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 (figure 21). The De Beers prospecting teams (then called De Beers Prospecting Botswana) were directed by Dr. Gavin Lament, with Jim Gibson the regional team leader. The actual discovery of the Orapa pipe, however, was made by Manfred Marx, a junior geolo- gist ("Young prospector. . . ," 1969; "How the Orapa pipe was discovered," 1971).Marx said to me once that "everyone has one great piece of luck during their lifetime of prospecting, and I had mine in my very first job" (pers. comin., 1994). Orapa turned out to be a pipe topped by an oval- shaped crater 1,560 in x 950 m and about 80 in deep. At 106.6 ha (263 acre), it was the world's second largest economic lzimberlite (after the 146 ha of Tanzania's Mwadui pipe). Bechuanaland became the independent state of Botswana in 1966, and in 1969 De Beers Botswana Figure 18. The Finsch mine has been a major South Mining Company (Debswana)was registered in African diamond producer since it was opened in 1967. Mining went underground when the pit- Gaborone to develop Orapa, originally as an 85/15 shown here in September 1990Ñha reached a joint venture of De Beers and the Botswana govem- depth of 430 m. inent. The Orapa mine started production in July 1971 and opened officially on May 26, 1972, with a planned production of 2.5 million carats per year the eastern (less sandy) parts of the country, and in ('Orapa opening . . . ," 1972; Alien, 1981).In 1975, 1965 they found two nondiamondiferous pipes near the joint venture was reorganized on a 50150 basis, Mochudi (Boocock, 1965). After 1960, they had also and the principals decided to double the size of the moved into the Motloutse River area, farther west Orapa operation. Orapa reached a peak production of than CAST had prospected. In April 1967, 12 years 6 million carats in 1991, and produced 5.4 million after they had started, they found a large diainondifer- carats in 1994 (De Beers Centenary Annual Reports ous lziinberlite pipe near a cattle post called Orapa for 1991-1994).

Figure 19. By building huge walls of sand to keep back the sea, CDM has mined vast tracts in Namibia that were once the I sea floor. Photo wur- Itesi of De Beers.

246 Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 Discovery of Letlhalzane. The Orapa pipe is part of a field that contains 30 lu~ownlzi~nberlites. One year after Orapa was discovered! De Beers Prospecting fo~indtwo small pipes! Letlhalzane 1 and 2 (I1.6 and 3.6 hal re~pectively)~abo~it 48 lzm southeast of Orapa, These two pipes came into production in 1976 at a projected annual rate of 3001000 carats (Allen! 198ljj in 1994) they produced 1 ,l million carats (De Beers Cenlena~Annual RgporL for 19941.

Discovery of Jwaneng. After the successful discover- ies of Orapa and Letlhalzane) De Beers vei~t~ired south into the Icalahari Desert and in 1973 discov- ered the Jwaneng pipe. Eleven pipes were event~ially found 25-60 m under a cover of ICalahari sand. Jwaneng forms three lobes-soutl~J central! and northeast-with a con~binedarea of 54 ha (133 acre] Fime The'ze~7n1h1mk Ore the Orfipa Wane1x2fl1x-l Lctfi(~lmne. The bst of these, Llnder50 of sand. mgstarted in ,.lie centrall 27 ha lobe (figure 22) in February 1982! at a planned the Orapa pipe, was discovered only in 1967. The Gape 25 is std bekm ev annual production rate of 5 million carats (Chadwicl~~1983); in 1994/ Jwaneng produced 9 inil- lion carats. deposits. Today! the River Ranch n1ineJ a single pipe) Prospecting by Falconbridge and Others. In 1974) a appears to be econoinic. Beca~isethe geologic frame- Falcol~bridgeIS~iperiorOil joint venture began worlz of Zimbabwe favors lziinberlite intn~sions~it prospecting in Botswana c0111binhg inchcator-miner- has been the object of considerable prospecting activi- a1 sampling with aeroinagnetic surveys (which will ty fi~recent years. be dcscribed in detail in Part H). Over the next five years! they found approximately 60 lzimberlites Alluvial Deposits. H. R. Moir! wllo had dLlg dia- Linda 20-60 in of sand. Although one of these pipes! monds at Vaal River! was the first to discover alluvial the Gape 2SJ appeared to have p~teiltiallnone of diamonds in the Soinabula Forest area! in 1903 these lzimberlites has yet proved economic. (Mennelll 1906; Macgregorl 1921). By arrangeillents h 1982) superior Oil withdrew and Falconbridge illade in 1892 with the British Soutll Africa formed two joint ventures with De Beers: Gope Company (founded by Rl~odes)~De Beers had an ExplorationJ to develop Gope 25; and Debridge exclusive license to mine all mineralsf includq dia- ~xploration~to investigate other areas (Jonesl 1982). monds! in Rhodesia. Therefore! Moir contacted NO econon~icdiscoveries have been announced to prolnhent entrepreneur Sir James w&u&byl who date. formed the South African Options Syndicate and Since 1988) smaller coinpanies based in used his influence to obt~a diamond-111-g con- Australia) Canada) and SOU~~IAfrica have joined the cessi~ilfrom ~e Beers. mgoperations started in search for diamonds. As of 1994) at least 140 lumber- 1905 but seldom an~o~~ntedto more than a few 11~1n- lites in 11 clusters or fields were known. Except for &ed carats amuallyj they haUy ceased h 1938. Orapa) wlich outcrops (again! see figure 20))all other lzimberlites in Botswana lie under 20-100 in of sand. fimberfite Rps. The f&t lzimberlite pipel ~~~ossu~~ No new major discoveries have been announced thus was found in 1907)about 80 lzm soutl~westof wel lo far) but it is highly probable that at least one more (Memelll 1908J1but it W~IS than col~~sd-dy siguficant diamond pipe mine will be found. 900 by 150 in. Several sinaller pipes were later found nearby! but all provcd to be ine economic. ZIMBABWE De Beers geologists found inore lzin~berlitesin (Formerly Southern Rhodesia) the central part of the countiy in the late 1930~~but HistoricallyJZimbabwehasbeenasmallproducerof tl~eres~~ltswerenotei~couraging.I~ii~~berlite diamonds fro111 alluvial and minor lziinberlite Searches has prospected intermittently since the

Dia~no~~dSources in Africa: Part I Winter 1995 are less lilzely to occur here than in Botswana and South Africa (where the platfor~nsediments are still present! so the upper! wider parts of pipes and craters could still be preserved). Neverthelessl several Canadian and Australian companiesl as well as Kiinberlite Searches! are actively prospecting throughout the country ("Zimbabwe diamond hunt expands! " 1994). About 30 lzimberlites had been found in Zi~nbabweas of mid-1995. To date! only the River Ranch pipe h~sproved econoinic.

Figure 21. This aeri~lview sl~owsthe Or(1po lzin~berlite River Ranch Mine. The River Ranch Iu~nberlitepipe pipe sl~ortlyober its discovery 1i7 1967. Ujdilze most was found in 1975 by IG~nberliteSexcl~es~ but was lzimberlites, the ciscular outhe of the pipe (lower right reported to be uneconomic (De Beers hnzzdReport foregro~ind)can be seen at the s~zrface.Photo courtesy for 1977). The mineral rights were returned to the of Manfred luarx. state and were then acquired by a joint venture between A~iridiain(Australia based) and Redaurum (Canada 17ased). They started a miling operation in early 1950~~adding to the number of uneconomic 1992 with a planned annual production of 3001000 kiinberlites discovered. carats; as of the end of 1994) llowever, production Since 1992! l~owever~prospecting activities have was a little over 1501000 ct (Holloway and accelerated due to a change in the mining law and Associatesl 1995). Evidence for the presence of veiy the promise of continued political stability! COIII- large diamonds is provided by the finding of large bined with discoveries of diainondiferous pipes in fragments from diamonds brolzen during recovely. Canada's Arcllaean shield (an area of ancient granitic Fragments of one large stone added iip to 326 ct. The roclzsl i.e.] inore than 2!500 ii~illionyears old). Most plant has been inodifiecl to recover large stones-LIP of Zin~babweis also underlain by an Arcliaean shield! to 40 inill in longest dimension-intact ("F~~rther biit the overlying platform sedn~entshave been erod- evidence . . . 1994). The mine was officially ed froin n~~ichof it. Therefore! large pipes and craters opened November 2! 1995. ZAIRE Figure 22. Botswana's enor~nouslys~~ccess~~l jwaneng ope11-pit mine, here as it loolwxl in 1992, (Formerly the Belgian Congo) prod~zced9 inillion carats of diamonds in 1994. In recent years! Zaire has been the largest dia~nond Photo courtesy of De Beers. producer in Africa (and second in the world after A~istralia)by weight! nearly 70 million carats duing 199 1-1 994. Altl~oughmost of the diainonds are recovered froin sands and gravels along watersheds and hillsidesl the highly prodiictive Mbuji-Mayi area derives large quantities of poor-qiiality stones from sinall luinberlites. Howeverl the oudoolz for diainond inining in Zaire is currently uncertainl beca~lseof chaotic social and political conditions.

Earliest Discoveries, The earliest dian~ondfind was made 111 Deceinber 1903 111 Icatanga (now Shaba Province] by two tin prospectorsl CooI

Diamond So~~rcesin Atrica: Part I GEMS ik GEMOLOGY Winter 1995 in the Lualaba hver during 1906 to 1909 (Ball! 1912) were traced to two groups of diai~~ondifero~~s~but uneconon~ic~lumberlites along the eastem and west- ein rims of the I

Tshilzapa. Belgian prospector Narcisse Janot found the first diainoi1d4.1 ct-in the Tshilzapa area on Noveinber 4) 1907! in the Icasai River at Mai Mu~lei~e(Ball! 1912). He was a member of a field Fig~re23. Alihoz~ghsome zrneconor~iicpipes party led by American geologist M. K. Shaler! whch have bee11 fozzi~dalong t11e caster11 and western was prospecting for tlle newly formed Societk rims of the Kundel~inguPlateazz, the major dia- Internationale Forestiere et Miniere du Congo 1n011ddej~osits iz~ Zaire are in the region of the (Formii~ikre)~a joint venture between (first Icing towns of Tsl~ilzapamd Mbuji-Mayi. Leopold and then) the Societk Genkrale de Belgicl~~e and tlle American Gu~eid~ein~-ThoinasRyan gro~ip. The Tslulzapa area was inhabited by the fiercely European-organized inking ended abruptly in l96lJ independent Batshiolzo tribes! which resented the after independence was attained! and has never been intn~sionof foreigners/ so a detachment of soldiers resunled, Virt~~allyall n~iningis now done by localsl acconlpanied the prospecting party. One can visual- who produce several hundred thousa~~dcarats a year ize the conditions when Janot was panning for gold: from this area. It was raining hard! the ilatives were hostile! and he After 1967! the national governinent tried to con- had been away fro111 lloine for nearly half a year. trol the diamond ii~d~~stryin Westein Kasai by allow- When he fo~~ncisome color in his pan (a few speclzs of ing expatriate companies to set up buying offices. yellow g01d)~he quicldy put tlle concentrate! whch Nevertheless! even today prod~~ctionand trade still included a bright slliny crystal) in 21 bag that eventu- are not controlled by the central government. The ally ended up in Brussels with all the other samples. number of carats purchased at the official buying P, L~mcsweert~who inspected Janotls samplesl recog- offices rose froin a few tho~~sandin 1968 to close to nized the crystal as diamondl and ShalerJs accurate 6OO10O0 annually in the late 1980s and 1990s. field notes helped then1 locate the probable discovery site (Buttgenbacl~~1910; "How diainonds were dis- Mbuji-Mayi. The first diamonds at Busl~imaie(now covered . . . 1925).The find was confirmed by Janot called Mbuji-Mayi)were found in December 1918 by in 191 1) when ruffled tribal feelings had settled George Young! a young Scottish geologst worlzing down. Mining started in 1913! and the Tsl~ikapa for the Compagnie des Chemins de Fer du Bas-Congo deposits became a steacly producer of good-q~iality au Icatanga (Bk~elza)~a railway company that had small stoiles (Bardet! 1974).They are still active. been granted huge tracts of land for mineral explo- At Tshilzapa/ diamoilds are found ii~~~nconsoli- ration (P01inard~1929). Young found more than 81800 dated sands and gravels in and along the Icasai hver sn~alldiainonds in one location in a tributaiy of the and its trib~~taries-Tshilzapa/ Loi~gatsl~i~~~o~Bushiinaie River. The Socikte M.inikre ~LIBecklza was Tsiuinbel and Lubeinbe-which flow north from the formed in 1919) and mining started at once with Lunda region of Angola into the I

Dii~n~ondSo~irccs in Africa: Part I GEMS &. GEMOLOGY came from several small lzin~berlites~hscovered in Angola will undo~lbtedlybe an even greater player on 1946 (de Magnee! 1947). Their pipe steins are veiy the international marlzet. narsow and are topped by sinall craters that contain a complex n~ixtureof sandstonel lumberlitel clay! cal- Alluvial Fields. The discovery of diamonds in the cite! opall and chalcedony roclz and mineral fsagments. Tshilzapa area of what is now Zaire encouraged the Diamonds were fo~mdin eluvial (cl~ectlyoverlying the Guggenheim-Ryan group to extend prospecting far- lzimberlite] and colluvial (transported down slopeJ1as ther upstream into tlie Lunda area of Angola. In July well as alluvial deposits in the stream beds. 1912! Donald Steel found the first diamonds in tribu- The diamonds were generally of poor q~dty(95% taries of the Luembe River (Legrandl 1984).The bort)' but the grade was high (5 carats per tonne] and Companhia de Pesquisa h'lineiras em Angola (Peina) mining was low cost (Bardet) 1974).Consequentlyl large was fo~lndedin Lisbon in 1913 to mine the dialnonds quantities were producedl racka peak of 18 don (Castsol 1929). Productionl which started in 1916! carats in 1961. This enonnous production has made a rose gradually from 1001000carats in 1921 to nearly signhcant impact on the world diamond marlzet. 8001000carats in 1940. Bkcklza was reorganized after independence into a In 1917! Pema was reorganized into the new new Belgian company! Sibelza (Socikte dfInves- Companlia de Diainantes de Angola (Diama~g)~and tissements de Bkcelza! later Socikt6 dfEntreprises et fouyears later Diamang acquired prospecting rights to d'Investissements)l whch formed a subsidiary Mha virtually all of Angola (except the coastal strip) until (Societk merede Balcwanga) to manage the Mbuji- 1971. Bamato Brothers and Anglo American purchased Mayi mines. The Congolese (after l97Ot the Zairian) large share holdmgs in Diainang in 1923' and secured a government took a 50% eq~~ityin Miba; this was contract that

250 Diamond So~~rcesin Africa: Part I GEMS & GEMOLOGY Winter 1995 Angola has a large illicit production (estimated at an additional one doncarats in 1992) that is largely ca~~sedby the recurrent den~obilizationof soldiers. Once released! the soldiers would rather dig for dia- monds than retum to their farms. Illicit production decreases when military operations talze place or heavy rains impede digging. A law passed in October 1994 gave Endiama the excl~~siveright to all diamond deposits in hgola and empowered it to enter into joint ventures with for- eign companies (with government approval). Licensed artisanal dggmg (manual diamond mining by local residents) is allowed in places where large- scale mmhg would not be lucrative. Present alluvial operations are carried out in the Lucapa area by ITL Mining (a s~lbsidiaryof RST) on behalf of the Sociedade Mineira de Lucapa! a joint venture of Endiama and SPE. Alluvial operations in the Cuango Valley! which stopped when Unita forces reinvaded the diamond worlu~~gsin November 1992! are starting up again. It is estimated that about 80% in of hgolan diamonds produced in 1980-1992 came Figure 24. Most of the diamonds fozmd to date Angola wme from allzzvid deposits h the Lz~capa from this area (Gordonl 1995). and Czz~7ngoareas,' in Lzznda Norte Provinc8. Kimberlites. There is only very limited production froin eluvial and colluvial gravels overlying pipes such All diamonds produced there to date came from all~l- as the one at Camaf~~ca-Camazombalwhich was vial deposits. The first diamonds were fo~~ndin 1914 found in 1952 in the Chicapa River near Caloi~da near Bria in the south central part of the country (Real! 1958). %s sinuous 3 lun-long bodyl up to 550 (Middleton! 1932). The major diamond-producing 111 widel covers an area of 75 ha (185 acres). Many regions are Camot-Berbkrati in C.A.R.Is wet ~0~1th- other chamondiferous lcimberlites were discovered in west and Moulza Ouadda in its dry northeast. the Lunda Norte district and elsewhere in Angola in Diamond production started in 1931. Mining was the 1970s (Jourdan! 1990, gives a total of 600). carried out by small French companies until indepen- Prospectmg activities by Diamang and E~~diamaindi- dence was attained in 19611after whcll syndicates of cated that at least five pipes in Lunda Norte may be locals assumed control. economic: CcamutuelCakepa! Cainatchia! Camagicq Since the early 1980~~foreign companies have and Catoca. However, hgo1a1s internal strife has hin- again been allowed to participate in mining ventures. dered evaluation and development of pipes throughout Osborne and Chappell Company attempted to dredge the country. The Russia-Salzha Diamond Corporation the Mambkrk River (the main trunlz river in the (Almazy Rossii-Sal~ha)~in a joint venture with Camot-Berbkrati region) during 1989-1 990) but the Endiama and Brazil-based Odebrecht) was reportedly project was terminated because the results could not pl- to develop the 66 ha Catoca pipe for open-pit support a large mechanized mining operation. mining. Development was delayed! tl~ough~as govem- Prospecting programs to evaluate the allegedly merit forces recaptured the Catoca area only in July extensive coll~~vialdeposits in the Ba~ningui- 1994 (Gordonl 1995). Bangoran area of the northeastern Moulza Ouadda De Beers is currently negotiating rights to region have been proposed since 1984. Canada-based prospect off-shore for submarine deposits and at sev- United Reef recently raised venture capital to evalu- eral areas on-shore (Gordonl 1995). ate this project (RoL~1994j1 and they started small- scale mining in June 1995. CENTRAL AFRICAN REPUBLIC (C.A.R.) Official plus unofficial production in C.A.R. is The Central African Republic has been a small b~~testimated at 50OI000 carats a~m~~allyfor the last 33 steady prod~~cerof diamonds since the mid-1930s. years (based on Mining Annuul Revjew reports for

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 with bright pebbles on De Kallz farm to liigh-technol- ogy exploration and excavation of tons of desert sand at Orapa and Jwaneng. During this period, all but two of the largest economic kimberlite pipes ever discov- ered were found (the other two are in Siberia). And several magnificent gem diamonds (see e.g., figure 25) were recovered. As a result, from 1872 to 1959, Africa produced 98% of the world's diamonds by weight, and 96% by value. Although, as will be dis- cussed in Part II, these percentages have dropped dra- matically in recent years, Africa is still the single most important diamond producer among the seven continents. Historically, most of the diamonds have been produced by alluvial diggings-along rivers and streams in South Africa, Angola, and Zaire, in partic- ular-and by large lzimberlite pipes, such as those clustered in the Kimberley area and the prolific pipes in Botswana. However, diamonds from coastal deposits, such as those off the Atlantic Coasts of Namibia and Namaqualand, promise to be the indus- try's greatest future resource. Part I1 will continue the story, focusing on the diamond-producing nations of eastern and western Africa. This part will also look at Africa's role in the development of theories on the geology and origin of Figure 25. The 128 ct fancy yellow Tiffanydiamond was diamond, as well as methods of diamond prospecting cut from one of the fabulous diamonds found in southern and mining. Special attention will be paid to the his- Africa, a 287 ct piece of rough reportedly recovered from a tory of diamond production in Africa and key devel- claim on the Kin~berleymine 111 1878. Photo by Josh opments from the 1870s to the present. Haskin; courtesy of Tiffany o) Co,

1961-1994). Despite careful prospecting, 110 lumber- Acknowledgments; The author [hanks Pat Sheahan htes or other primary host rocks have been found in of Konsult International Inc. in Toronto for assistance this region, and all of C.A.R.'s diamonds are recov- in collecting basic information and literature refer- ered from alluvial sources. ences; Roz Llavies of Creative Cartography in Perth for making the maps and last-minute alterations; Drs. CONCLUSION TO PART I John J. Gurney and Alfred A. Levinson for constnzc- The history of diamond and kimberlite discoveries in tive reviews, and Dr. Levinson especially for his Africa spans nearly 130 years, from children playing meticulous scrutiny of the maps and references.

REFERENCES Allen H.E.K. (1981) Development of Orapa and Letlhakane dia- Engineering journal, Vol. 40, Part 2 (November), pp. 573-574. mond mines, Botswana. Transactions of the Institution of Atherstone W.C. (18691The discovery of diamonds at the Cape of Mining and Metallurgy (Section A: Mining Industry), Vol. 90, Good Hope. Geological Magazine, Decade 1, Vol. 6, pp. October, pp. A1 77-A191. 208-213. The Angolan diamond deal (1923) South African Mining and Atkinson W.J., Smith C.B., Danchin R.V., fanse A.J.A. (1990) Engineering Journal, Vol. 34, Part 2, January 20 (p. 515) and Diamond deposits of Australia. In F.E. Hughes, Ed., Geology of February 3 (p.5751. the Mineral Deposits of Australia and Papua, New Guinea, The Angolan diamond experrcncc: A case of wasted opport~~iiily Vol. 1, Australasian Institute of Mining and Metallurgy, (1992)Diamond World Review, No. 71, pp. 44-59. Melbourne, Australia, pp. 69-76. Another great clicinionil discovery (1928) South African Mining and Babe J.L. (1872) The South African Diamond Fields. D. Weslcy &

Diamond Sources in Africa: Part 1 GEMS & GEMOLOGY Winter 1995 Co., New York (reprinted in 1976 by the Historical Society, tifcre de Bakwanga (Kasai, Congo Belge). Bulletin de la Societi Kirnberley, South Africa), 105 pp. Belge de Geologic, Vol. 56, No. 3, pp. 97-108. Balfo~~r1. (1992) Famous Diamonds, 2nd ed. Gemological Institute Diamonds are trumps (1867)Cape Argus, April 18, p. 1; as reported of America, Santa Monica, CA, 245 pp. in Robertson, 1974, p. 43. Ball S.H. (1912) Diamonds in the Belgian Congo. Enguieering and Diamonds founil near Mlihash on the Lcbombo Range, cast of Mining journal, Vol. 93, No. 5 (February31, pp. 268-269. Swaziland (1895) South African Minirig jo~trnal,Vol. 4, January Ball S.H., Shaler M.K. (1914)Economic geology of the Belgian 12, pp. 299-300. Congo, Central Africa. Economic Geology, Vol. 9, No. 7, pp. Diamonds mined off the sea bed (1962) Mining Magazine, Vol. 605463. 107, No. 1 (January),p. 40. Bardet M.G. 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(1904) The diamond placers of the Vaal River, South and William Spottiswoodc, London. Africa. Transactions of the Institution of Mining and Hawthorne J.B., Carrington A.J., Clement C.R., Skinner E.M.W. MetaU~ugy,Vol. 13, pp. 518-532. (1979) Geology of thc Dokolwayo hberlite and nssociateil Colonel Jack Scott finds first diamonds in Maluti Mountains, 1954 palaeo-alluvial deposits. In F.R. Boyd and H.O.A. Meyer, Eds., (1978)Indiaqua, No. 18, pp. 19-20. Kimberlites, Diatremes, and Diainoiid.~:Their Ceology, Croll A.M., Cooper G. (1993)Auchas n~c:Its discovery, its rnin- Petrology, and Geochemistry, Vol. 1, Proceedings of the ing and its future. In Abstracts of the Conference on Milling Second International Kimberlite Conference, American Investment in Namibia, Ministry of Mines and Energy, Geophysical Union, Washington, DC, pp. 59-70, Windhoek, Namibia, pp. 89-91. Helme N. (1974)Thomas Major CuUinan, a Biography. McGraw- Dawson J.B. (1962) Basutoland kimberlites. 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Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 253 How diamonds were discovered in the Belgian Congo (1925) Mining Annual Review 1995 (1995)The Mining Journal, London. Engineering and Mining Journal, Vol. 119, No. 2, p. 43. Molengraaff G.A.F. (1895) Uber ein Vorkommen von Diainanten How the Orapa pipe was discovered (1971) Diamond News and in dem Bebiete der kohlennjhrenden Formation bei Driekop im S.A. IeweUer, February, pp. 7-10. Oranjc-Freistaat (About the occurrence of diamonds in the area Hubner A. (1871) Geognostische Skizzen von den Sud- of the coal-bearing formation near Driekop in the Orange Free Afrikanischen Diamanten-Districten. Petermiinn State). Neues lahrbuch fin Mineralogie, Band 1894195, pp. (Geografische) Mitiheiliuigen, Vol. 17, No. 3, pp. 8 1-87. 277-283. Jacobs' diamond was not the first (1867)Colesberg Advertiser and Molengraaff G.A.F. (1897) Diamoncl at Rietfontein. Transactions Northern Frontier Gazette, June 4. of the Geological Society of South Africa, Vol. 3, pp. 122-123. Janse A.J.A. (1975)kmberlitc and related rocks from the Nama Molengraaff G.A.F. (1905)Thc Cullinan diamond. Transactions of Plateau of South-West Africa. Physics and Chemistry of the the Institute of Minmg Engineers, Vol. 24, pp. 507-509. Earth, Vol. 9, pp. 8 1-94. Murray L.G., Joynt R.H., O'Shea D.OfC.,Foster R.W., Kleinjan L. Jeffries D. (1750) A Treatise on Diamonds and Pearls. London. (1970)The geological environment of some diamond deposits Jones A. (1982)Falconbridge plans Dc Beers link for diamond off the coast of South West Africa, Report no. 70113. In F.M. search in Africa. Northern Miner, Vol. 68, No. 34 (October 281, Dclaney, Eel., The Geology of the East Atlantic Continental pp. 1, 19. Margin, Natural Environment Research Council, Institute of Jourdan P. (1990) The Minerals Industry of Angola. University of Geological Sciences, Her Majesty's Stationery Office, London, Zimbabwe Institute of Mining Research Report No. 116, pp. 9- pp. 119-141. 11. Murray R.W. (1873)The diamond-field keepsake for 1873. Saul Kaiser E. (1926) Die Diamantwijste SiidwestafriINorth America, Nelly Jacobs, the little diamond finder (1867)Colesberg Advertiser 2nd ed. (Reprinted in 1967 by Dover Publications, New York, and Northern Frontier Gazette, July 30, p. 1. 367 PP.) Nixon P.H., von Knoning O., Roolic J.M. (1963) Kimberlites and Kunz C.F. (1929) Precious and semi-precious stones. In G.A. associated inclusions of Basutoland: A mineralogical and geo- Rousch, Ed., The Mineral Industry: Its Statistics, Technology chemical study. American Mineralogist, Vol. 48, No. 9/10, pp. and Trade d~~rir~g1928, Vol. 37. McGraw Hill Book Co., New 1090-1 132. York, pp. 512-537. Noble J. (1874)The diamond fields of South Africa. Temple Bar, Legrand J., Ed. (1984)Diamonds, Myth, Magic and Reality, rev. ed. Vol. 41, pp. 385-400. Bonanza Books, New York, 287 pp. Orapa opening marks 17 years work (1972) Diamond News and Leliinan 0. (1955) Look Beyond the Wind: The Life of Dr. Hans S.A. jeweller, July, pp. 17-23. Merensky. Howard Timmins, Cape Town, South Africa, 183 Paterson J. (1873)On a visit to the diamond fields of South Africa. PP. Proceedings of the Geological Association, Vol. 3, pp. 70-80. Lengthy wait for weightier diamonds in Lesotho mountains (1978) Polinard E. (1929) Les diainants translucides et opaques des gise- Indiaqua, No. 18, pp. 1 1-18. ments de la Bushirnaie. Annales de la Sociiti G6ologi~ede Leiizen G. (1970) The History of Diamond Production and the Belgipe, Vol. 52, pp. C179-C186. Diamond Trade. Barrie and Jenldns, London, 230 pp. Precious stone at the Cape of Good Hope (1867) Journal of the Lcvinson 0.(1983) Diamonds in the Desert. Tafelberg Publishers, Society of Arts, Vol. 15, October 4, p. 703. Cape Town, South Africa, 172 pp. The Premier mine, the world's biggest diamond mine (1903)South Liddicoat R.T., Ed. (1993) The GlA Diamond Dictionary, 3rd ed. African Mines, Commerce and Industry, Vol. 1, Part 1 (June Gemological Institute of America, Santa Monica, CA. 27), pp. 344446. Macgregor A.M. (1921)The geology of the diamond-bearing gravels Premier (Transvaal) Mining Company-washing results (1903). of the Soniabula forest (with notes by A.E.V. Zealley). Bulletin African World, Vol. 2, February 14, p. 1 1. of the Southern Rhodesian Geological Survey No. 8, pp. 7-38. Real F. (1958) Sur les rochcs lcimberlitiques de la Lunda (Angola). Matthews J.W. (1878) Incwacli Ya~ni,or Twenty years' Personal Boletim de Muse~ie Laboratoria Minerals e Geologico. Experience in South Africa. Rogers &. Sherwood, New York, Faculdad Ciencias, Universidad de Lisbon, Series 7, No. 26, 542 pp. pp. 220-253. Mennell F.P. (1906) Somabula diamond field of Rhodesia. Reunert T. (18931Diamonds and Gold iri South Africa. J.C.Juta & Geological Magazine, Decade 5, Vol. 3, No. 508, pp. 459-462. Co., Cape Town, South Africa, 242 pp. Mennell F.P. (1908) Note on the Rhodesian Diamond Fields. Reuning E. (1928) The discovery of the Namaqualand diamonds. Transactions of the Geological Society of South Africa, Vol. 11, Mming and Industrial Magazine of South Africa, Vol. 7, pp. pp. 43-44, 51-55,87-91,141-143,219-221, and 265-267. Merensky H. (1904)Technical report on the Premier mine. South Robertson M. (1974)Diamond Fever, South African History African Mining Journal, Vol. 2, Part 2 (September 101, pp. 1866-9, from Prin~mySources. Oxford University Press, Cape 582-584. Town, South Africa, 250 pp. Merensky H. (1909)The Diamond Deposits of Luderitzlancl, Rose G. (1837)Mineralogisch-geognostische Reise nach dem Ural, German South-West Africa. Transactions of the Geological dem Altai und dem Kaspischen Meere, Erster Zweiter Band, Society of South Africa, Vol. 12, pp. 13-23. Reise nach dem nordlichen Ural und dam Altai. Sanderschen Meyer H.O.A. (1991) Marine diamonds off southern Africa. Buchhandhmg (C.W. Eichhoff), Berlin, 641 pp. Diamond International, MarchIApril, pp. 49-58. Roux J. (1994) Canadians lead revival in the C.A.R. Diamond Middleton J.L. (1932) Diamonds in Equatorial Africa. Engineering International, Maynune, pp. 91-92,95-96. and Mining Journal, Vol. 133, No. 5, P. 285. Sarmento J. de C. (1735) Historical accounts of the discovery of

254 Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 gold and dianionds in Minas Gerais. Materia Medica-Physico- Unpublished report, Bechuanaland Geological Survey Historio-Mechanics, Regno Mineral 1, Lon~lon,pp. 149-154. Department. Scheibe R. (1906)Der Blue Ground des Deutsch Slidwest Afrika Weakley J.R. (1869)The diamond discovery in South Africa (a col- in1 Vergleich mit dem des englischen Slid Afrikas (The blue lection of articles and original correspondence from various ground of German South West Africa compared to that of colonial journals and original remarks refuting erroneous state- Enghsh South Africa). Programni der konighchen Be1plcademie ments by H. Emanuel and J.R. Gregory]. Colesberg Advertiser, zu Berlin, FeistelJschen Buchdruckerei, Berlin, 18 pp. Colesberg, South Africa, 35 pp. Sheparcl C.U. (1846)On three new mineral species from Arkansas, Webster R. (1975) Gems: Their Sources, Descriptions and and the discovery of diamond in North Carolina. American Identification, 3rd ed. Butterworth & Co., London. fovmal of Science, 2nd ser., Vol. 22, pp. 249-254. Williams G.F. (1905) The Diamond Mines of South Africa. Sinkankas J. (1976) Gemstones of North America, Vol. 2. Van Macndan Co., New York. Nostrand Reinhold, New York. Williams A.F. (1930) Diamond bearing gravels of the Union of The Sterldontein diamond diggings (19231 South African Mining South Africa. In Proceedings of the Third (Triennial) Empire and Engineeringlowial, Vol. 35, No. 1648, pp. 152-153. Mining and Metallurgical Congress, South Africa, March 24- Steytler J.G. (1870)Letter, dated July 23, reporting the discovery of May 8, Part 3, Paper 2, 169 pp. diamonds on Jagersfontein. In The Emigrant's Guide, the Willianls A.F. (1932) The Genesis of the Diamond, Vols. 1-2. Diamond-Fields of South Africa, Saul Solomon, Cape Town, Ernest Berm, London, 636 pp. South Africa, p. 18. Williams G.F. (1886) The diamond mines of South Africa. Stockley G.M. (1947) Report on the Geology of Basutolancl. Transactions of the American Institute of Mining Engineers, Government Printer, Maseru, Lesotho, 114 pp. Vol. 15, pp. 392417. Tennant J. (1870)South African diamonds. fournal of the Society Williams G.F. (19051 The Diamond Mines of South Africa, Vols. of Arts (London),Vol. 19, November 25, pp. 15-19. -2. B.F. Buck &. Co., New York. Twenty diamonds found so far along the banks of the Orange Wilson A.N. (1972)Spectacular finds in the Orange River terraces. River, see map (1868)Cape Argus, October 31. In A. N. Wilson, Diamond International No. 2, Diamond Wagner P.A. (1914)The Diamond Fields of Southern Africa. The International (Pty.)Ltd., Johannesburg, pp. 53-54. Transvaal Leader, Johannesburg, South Africa (reprinted in The wonderful South African diamond (1867) Colesberg 1971 by C. Struik, Cape Town, South Africa, 355 pp.). Advertiser and Northern Frontier Gazette, April 9. Wagner P.A., Merensky H. (19281 The diamond deposits on the Young prospector carved niche for himself in history (1969) coast of Little Namdqiialand. Transactions of the Geological Diamond News and S.A. leweUer, September, pp. 18-19. Society of South Africa, Vol. 31, pp. 1-41. Zimbabwe diamond hynt expands (1994)Diamond International, Wayland E.J. (1949)Minerals in the Bechuanaland Protectorate. No. 29, May/June, pp. 23-24. ,. , IN RESPONSE TO POPULAR DEMAND... 1

For more information or to enroll ddl(600) 421-7250 ext. 2% Outside the U.S. (3 10) 829-299 1 ext '2 Fax (3 10) 453-7674 SPECIAL I am hrn-At-mme i, [I INTRODUCTORY TUITION:

Diamond Sources in Africa: Part I GEMS & GEMOLOGY Winter 1995 OF NATURALAND

By James E. Shigley, Emmanuel Fritsch, Ilene Reinitz, and Thomas M. Moses

A chart is provided that describes those ow that small numbers of gem-quality synthetic dia- gemological properties thai are key to the monds have begun to appear in the jewelry industry, it separation of gem-quality yellow, blue, and has become critical that the professional jeweler/gen~ologist near-colorless (to colorless) natural dia- have the skills not only to quality grade a diamond, but also monds from synthetic diamonds. This for- to identify that it is a natural, untreated stone. This article mat was designed to give jewelers and accompanies a chart that describes the distinctive geinologi- gemologists a ready reference to identify synthetic diamonds as they enter the jewel- cal properties of natural as compared to synthetic gem dia- ry trade. Magnification and luminescence monds (figure l).In particular, the chart was designed to bring are the most important testing techniques together in summary form those characteristics of gein-quali- currently available to jewelers and gemolo- ty synthetic diamonds that will enable jewelers and gemolo- gists. The most distinctive features of syn- gists to readily distinguish them from natural diamonds. This thetic diamonds include color zoning, article describes the information contained in the chart, how graining, metallic inclusions (often n~aking it is organized, how it can be used m a standard gem identifi- the stone magnetic), and uneven ultraviolet cation procedure, and how the diagnostic gemological fea- fluorescence. tures can be resolved or recognized using standard gem-test- ing equipment. Some additional data, obtained through advanced techniques such as energy-dispersive X-ray fluores- cence chemical analysis, infrared spectroscopy, and cathodo- luminescence, are also cited because they provide useful information that the well-equipped gem-testing laboratory can use to support a conclusion. With this chart, jewelers and gemologists alilze have the means to identify the variety of gem-quality synthetic diamonds available at this time (see Box A).

BACKGROUND Over the past several years, various gemological researchers have published information on gem-quality synthetic dia- monds and their practical gemological identification. Important articles include those by Crowningshield (1971), ems & Gpotogy, Vol. 3 1, No. 4, tSS5, Koivula and Fryer (19841, Shigley et al. (1986, 1987, 1993a, '). ,256-264 1995), Ponahlo (1992))Rooney et al. (19931, Moses et al. (1993a), Scarratt et al. (1994),Kanda and Lawson (1995).and Sunagawa

256 Diamond Chart GEMS & GEMOLOGY Winter 1995 Figure 1. Shown here are some of the synthetic diamonds examined by GIA researchers to date (clockwise from top photo): (1) three faceted (0.39 ct yellow, 0.31 ct grayish blue, and 0.30 ct near-colorless) synthetic diamonds and one crystal (0.73 ct near-colorless) grown experimentally by General Electric; (2)three Sumitorno yellow crys- tals (top, 0.63-1.07 ct) and four yellow synthetic faceted stones (0.16-0.24 ct); (3) a 0.14 ct synthetic diamond with a dark red color caused by treatment; (4)De Beers experimental yellow synthetic diamonds-0.30 ct (left), 0.27 ct (right), and a 1.03 ct crystal (top); (5)a 0.42 ct near-colorless crystal produced in Russia; (6) two yellow Russian us-grown crystals (left, 0.78 ct; right, 0.88 ct), plus three as-grown (0.18-0.51 ct) and two treated (0.14-0.21 ct) faceted synthetic diamonds. Photos are by, ogain clockwise from top, Tino Hammid (first two), Shane F. McClure, Tino Hammid, Shane F. McClure, and Robert Weldon.

Diamond Chart GEMS & GEMOLOGY Winter 1995 25 7 Box A: A PRACTICALGUIDE FOR SEPARATING NATURALFROM SYNTHETICDIAMONDS

Synthetic diamonds have a number of gemological to confirm a preliminary identification made on the properties by which they can be identified reliably. basis of internal features, you would look next at the However, this requires that jewelers look at diamonds reaction to long- and short-wave ultraviolet (UV)radia- more carefully, and document more properties than tion. In most instances, there will be some distinguish- they traditionally have documented. The following is a ing fluorescence features present. In the past, the fluo- step-by-step procedure, to be used in conjunction with rescence reactions of diamonds were not perceived as the information and illustrations on the chart, by which key identifying features by the jeweler or gemologist, synthetic diamonds can be identified by any trained who was solely concerned with grading concepts such gemologist using standard gemological equipment. as the strength and color of the reaction to long-wave UV radiation. For grading purposes, the diamond is MAGNIFICATION placed table down under a long-wave UV light source in The first step in grading, appraising, or purchasing a dia- partial darkness. For identification purposes, it is prefer- mond is to examine the stone with n~agnification,prefer- able to view the stone from all directions, under both ably with a gemologi~almicroscope. This procedure, in wavelengths of UV light, in total darkness. In the latter which the observer determines such important informa- case, the pattern (or zoning) of the fluorescence is often tion as the clarity and other grading parameters, is also more important than the fluorescence color. critical to detenliirung whether the diamond is natural A natural diamond typically fluoresces blue to or synthetic. long-wave UV (LWUV) radiation, with a weaker and Careful observation of the inclusions present often usually yellow reaction to short-wave UV (SWUV).This reveals the identification of the diamond conclusively. fluorescence is usually evenly distributed, but it may be For example, an included crystal of a transparent guest planar. Conversely, synthetic diamonds typically fluo- mineral such as garnet, enstatite, or diopside-or of resce yellow to yellowish green to both LWW and another diamond-identifies the diamond as natural. SWUV, with the reaction often noticeably stronger to Conversely, if you see a dark, opaque inclusion, you short-wave than long-wave. In addition, the internal would want to look at it very carefully using such light- growth sectors of a synthetic diamond generally pro- ing methods as fiber-optic illumination to determine if duce a cross-shaped, octagonal (or similar geometric) its luster is reflective and metallic (figure A-1). If so, it pattern of fluorescence to either or both wavelengths. might be a piece of metallic flux, in which case testing I11 some cases, fluorescence may be stronger to for magnetism (see below) would be sufficient to prove LWUV than to SWUV, or the reaction to both wave- that it is a synthetic. lengths may be similar in strength, unlike the notice- In situations where the diamond is of higher clarity able difference in intensity usually present in natural and no diagnostic inclusions are present, close examina- diamonds. Low magnification can be useful to observe tion of growth features may aid in identification. any zoning of the fluorescence reaction. (AnOptivisor is "Hourglass" graining, which is usually visible through well-suited for this purpose; if a microscope is adapted the pavilion, is related to the octahedral and cubic inter- for this use, precautions should be taken to shield the nal growth sectors of synthetic diamonds. Consequently, operator's eyes from the short-wave UV radiation.) the presence of hourglass graining is proof that the dia- Ultraviolet fluorescence is a test con~monlyused by mond is synthetic. Any graining (colorless, colored, jewelers and gen~ologists,and simple observations such whitish, green, or even surface graining) following the as these may identify the diamond conclusively. In addi- octahedral planes throughout the stone would indicate tion, an entire parcel of stones can be tested at one time. that the diamond is natural. Likewise, phantom graining along the octahedral directions would also serve to iden- SPECTROSCOPY tify a diamond as natural. To date, most of the gem-quality synthetic diamonds In a colored diamond, any color zoning observed can encountered in the trade have been yellow to brownish be useful for making the identification; examination with yellow in body color; they have been identified as syn- diffused transmitted light is very helpful in this regard. thetic during the testing procedure used to determine Natural diamonds may show planar bands of color or a their "origin of color." Observation of the spectniin- roiled effect, but only synthetic diamonds would show with a prism or diffraction-grating [hand-held or desk- patterns related to the internal growth sectors. model) spectroscope-is a routine test for colored dia- monds. The spectra of most natural diamonds, whether ULTRAVIOLET FLUORESCENCE of natural or treated color, differ from those seen in syn- If no diagnostic features are seen with magnification, or thetic diamonds. The most common spectral features

258 Diamond Chart GEMS & GEMOLOGY Winter 1995 seen in natural diamonds are the "Cape" lines at 415 nnl and at 452, 465, and 478 nm. On the basis of the samples we have examined to date, we believe that the presence of a 415 nm line in a colorless to light yellow diamond can be considered proof that the stone is natural. Treated-color natural diamonds may show addi- tional absorptions at 496, 503, 595, or 637 nm. Such spectral features suggest that the diamond is natural (even if the color is treated). Absence of the 415 nm he would not prove that the diamond is synthetic, but it would make it necessary to test the stone further. Some synthetic diamonds show a number of absorption lines between 470 and 700 run (see chart], which are due to the nickel used in the flux. Observation of several of these lines would indicate a synthetic. However, most colored synthetic diamonds are predominantly type Ib, so no sharp absorption fea- tures are expected in the visible spectrum. Rarely, natu- ral diamonds are type Ib or type IIa, and these are not expected to show spectral lines.

MAGNETISM The metal fluxes used to help grow synthetic dia- monds often leave metallic inclusions-from subini- croscopic particles to eye-visible pieces-in the syn- Figure A-1. A group of metallic inclusions is seen thetic stone. Such inclusions are magnetic and may here under the tablefacet of a brownish yellow be attracted by a strong magnet. To detect this mag- synthetic diamond. Although the square shape of netism, the diamond can be suspended from a string the inclusions is somewhat II~LISII~,their and sheltered against air currents, while the magnet is opaque appearance in transmitted light is very placed close to the stone (but not touching it). Moving characteristic. Photomicrogropl~by John I. the magnet from side to side should induce a parallel Koivula; magnified 25x. motion in a synthetic diamond, but will cause no movement in a natural stone. As mentioned above, observation of a dark inclu- patterns and bright interference colors, whereas the sion with a metallic luster would lead you to perform strain present in synthetic diamonds shows a cross-like this test, although finely dispersed flux that is not pattern in subdued colors, mainly black and gray. resolvable under magnification may also react to a magnet. Thus, a clear response of the diamond to the SUMMARY magnet proves that it is synthetic, but lack of a mag- Whether the diamond is ultimately to be examined for netic response only suggests that it is natural. In rare grading or for its origin of color (procedures that differ instances, a natural diamond may contain inclusions considerably), you can determine the stone's natural or that cause the stone to be faintly attracted to a strong synthetic origin by using one or more of these basic magnet, but such a diamond will undoubtedly have gemological tests: other properties that prove it to be natural. 1. Examine the stone with magnification, looking for inclusions, color zoning, and graining. STRAIN 2. Observe the UV fluorescence, especially with the Anomalous double refraction (ADR),commonly called stone in the face-up position, looking for both a 'strain," is a characteristic of diamonds that normally fluorescence pattern and the relative strength of goes unnoticed by the jeweler or gemologist, although it fluorescence to LWUV and SWUV. is well known to diamond manufacturers. It can be observed by holding the diamond from table to culet 3. Look at the spectrum with a hand-held or desk- under a polariscope or between crossed polarizing filters model spectroscope. attached to a gemological microscope. Although this is 4. Check whether a suspected synthetic reacts to a not a "stand-alone" test, it is particularly useful when strong magnet, the stone is free of inclusions, is of high color, or shows no "Cape" series in the spectroscope. Natural diamonds 5. If necessary, observe the strain patterns/colors generally show banded, cross-hatched, or mottled strain between crossed polarizers.

Diamond Chart GEMS & GEMOLOGY Winter 1995 (1995).Other articles, taken mainly from the geino- Antwerp (van Royen, 1994, p. 44). A 2.32 ct brown- logical literature, are provided in the "Additional yellow brilliant-cut pear-shaped synthetic diamond Reading" addendum to the "References" list. The was reported by the Gemmological Association of purpose of all these articles has been to inform the Great Britain Gem Testing Laboratory in London jewelry trade (and, indirectly, the public at large) (Emms, 1994). Synthetic yellow diamonds from about synthetic gem diamonds from various inanu- Russia have also been examined by gemologists in facturers (in particular, experimental samples from Germany (Hem and Bank, 1993), Thailand (Scarratt General Electric and De Beers, and commercial mate- et al., 1994), and Italy (Sosso, 1995). The largest rial from S~~n~itoinoand various Russian laboratories faceted synthetic diamond known to date is a 5.47 ct [again, see figure I]).The articles have also demon- brownish yellow stone (cut as a round brilliant) that strated how to identify those gemological characteris- was identified in early 1995 by staff members of GIA tics that trained jewelers and gemologists can use to GTL. Despite the limited numbers of synthetic dia- separate synthetic diamonds from their natural coun- monds seen, the fear that they will enter the marlzet- terparts. place and will not be readily identifiable continues to We believe that, to date, synthetic diamonds of a haunt the trade (see, e.g., Costan, 1993; Nassau, 1993; size and quality suitable for faceting have been grown "Chatham to sell 'created' diamonds," 1993; Helmer, only in limited numbers and have had little, if any, 1994; Howard, 1995). adverse impact on the jewelry industry. However, as Most synthetic diamonds are brownish yellow to the costs of production go down (with improvements yellow, but blue and near-colorless crystals have also in the technology of diamond synthesis), it is possible been grown in limited numbers, thus far primarily for that such synthetics will be less rare in the future. experimental purposes. In all colors, samples suitable The only synthetic diamonds encountered in the in size and quality for jewehy use have been faceted. trade by the GIA Gem Trade Laboratory (GIA GTL) According to the research work published to have been yellow (10 samples seen since 1987 with date, those synthetic diamonds available thus far nine of these seen since 1993: see, e.g., Moses et al., have several distinctive gemological properties that 1993b; Kainmer~et al., 1993, 1995b)or red (thee allow for their identification using readily available samples seen, all with the color due to laboratory gem-testing techniques. For both as-grown and labo- treatment; the first two are described in Moses et al., ratory-treated colored synthetic diamonds (which 1993a).A faceted 1.23 ct brown-yellow synthetic dia- tend to have saturated hues), we have found that the mond was examined by staff members of the Hoge most diagnostic gemological properties are certain Raad voor Diamant (HRD)certificates laboratory in patterns of uneven color; uneven yellow to yellowish

Figure 2. Natwal diamonds, like the 0.69 ct near-colorlessstone shown here on the left, typically fluoresce a rela- tively even blue to long-wave UV radiation. In contrast, synthetic diamonds, like this 0.13 ci yellow synthetic on the right, typically fluoresce yellowish green to short-wave UV radiation, with an uneven (cross-like)pattern (the blue color at the lower right is merely a reflection of the UV lanlp). Photomicrographs by Jolm I. Koivula; magni- fied 5x (left) and 15x (right).

260 Diamond Chart GEMS & GEMOLOGY Winter 1995 green ultraviolet (W)fluorescence (figure2)) which is often stronger to short-wave (SWUV)than long-wave (LWUV)ultraviolet radiation; and certain graining patterns, as well as the presence of metallic flux inclusions. For near-colorless to colorless synthetic diamonds, the diagnostic properties are certain pat- terns of uneven UV fluorescence [so far, always stronger to SWUV), persistent phosphorescence, and metallic flux inclusions. The zonation of color, UV fl~~orescence,and graining that is often so pronlinent in synthetic dia- monds results from their internal structure, which contains octahedral, cubic, and sometimes additional growth sectors. Chemical impurities trapped from the laboratory growth environment are concentrated either along the boundaries between internal growth I sectors, or in one sector and not in adjacent ones, in Figure 3. The Lnminoscope, manufactured by the synthetic diamond crystal (sec Kanda and Premier American Technologies Corp., consists Lawson, 1995).The distinctive features of as-grown of twoparts: On the left is the vacuum chamber synthetic diamonds result from those conditions of and electron "gun," and on the right is the power diamond formation in the laboratory that differ from supply and control unit Diamonds will emit vis- those in the earth (mostly in that diamonds are ible catl~odol~uz~~~escei~cewhen they are bom- grown in a silicate solution in nature and a metallic barded by the election beam in the vacuum solution m a laboratory; see Sunagawa, 1984, 1995). chamber. Photo courtesy of Premier American The color of brownish yellow synthetic dia- Technologies Corp., Bellefonte, Pennsylvania. monds can be altered to either pink to red, or yellow to greenish yellow, by treatment processes such as irradiation followed by heating (Moses et al., 1993a), or heating at high pressure (Shigley et al., 1993a), information to properties of faceted natural or syn- respectively. These treatment processes will also thetic diamonds that could be documented readily by alter gemological features such as W fluorescence gemologists, although some other features such as and absorption bands seen with a hand spectroscope crystal size and shape are included. Sunagawa (1995) [see italicized text on chart). Nevertheless, a treated provides a comprehensive discussion of the differ- synthetic diamond is no more difficult to detect than ences in morphology, surface features, and internal its untreated synthetic counterpart. characteristics of rough natural and synthetic dia- Although there are many similarities in gemo- mond crystals. logical properties anlong synthetic diamonds from Some information derived from three other iden- various manufacturers, "and among those treated by tification techniques-cathodol~~minescence, energy- different processes, there are also some differences. It dispersive X-ray fluorescence (EDXRF)chemical anal- is because of this that we decided to bring together in ysis, and infrared spectroscopy-is also included on chart form those features that we currently know to the chart. We believe that cathodoluminescence be useful in the identification of synthetic diamonds. [luminescence generated by exposure of a material to a beam of electrons in an evacuated chamber), in par- ticular, will soon become a more standard technique CONTENTS OF THE CHART for testing diamonds in gemological laboratories (see The chart presents information on synthetic (both as- Ponaldo, 1992, and photographs of cathodolumines- grown and laboratory-treated) dianlonds and their cence in Shiglcy et al., 1987, 1993a).A relatively sim- natural counterparts in a vertical format organized by ple unit (known as a Lun~inoscope),which is capable three general color groups: yellow, colorless to near- of generating catl~odol~~minescencein diamonds and colorless, and blue. For each general color group, we other gemstones, can be purchased for about have summarized only the most useful gemological US$20,000 (figure3). It consists of a sample chamber properties. For the most part, we chose to restrict (from which the air can be evacuated, and which can

Diamond Chart GEMS & GEMOLOGY Winter 1995 Figure 4. The natural diamond on the far left shows the relatively even blue cathodoluminescence typical of nat- vial diamonds. However, some natural diamonds (center) exhibit a cathodoluminesce~~cepa~ern that reflects their complex growth history. Nevertheless, these patterns are distinctly different from the green-to-yellow, cross-shaped cathodoluminescence pattern typically seen in synthetic diamonds (here, a costal gown experi- mentally by De Beers). Photo on the left is by Maha DeMaggio (magnified 54; center and right photos are by Michael Crowdcr, De Beers Research Centre, Maidenhead, UK (magnified 6xand 2x, respectively). be mounted on a n~icroscopestage, if desired) with a number elements-such as carbon, nitrogen, or viewing port, a "gun1' that emits an electron beam, boron-typical of the major- and trace-element chem- and the associated power supply. Our observations istry of natural diamond). On rare occasions, natural indicate that no diamond, natural or synthetic, is diamonds with mineral inclusions (such as garnet) inert to cathodoluminescence [which is not the case may exhibit evidence of trace amounts of Si, Al, Fe, with W fluorescence).In addition, although the col- Mg, or Ti. Diamonds polished on an iron scaife may ors of luminescence generated by W fluorescence exhibit features consistent with Fe contamination. and cathodoluininescence may differ, the characteris- Finally, we have included information that refers tic pattern of internal growth sectors in a synthetic to diamond type (e.g., la, Ib, IIa, IIb), a traditional diamond can often be seen more easily using scheme used to classify all diamonds on the basis of cathodolurninescence (figure 4). In those cases where their nitrogen and boron contents by means of the W fluorescence is weak or indistinct, in particu- infrared spectroscopy (for a good, concise discussion lar, we have found that the more intense cathodolu- of diamond type, see Fritsch and Scarratt, 1992, pp. minescence will reveal the presence of different inter- 38-39). This classification of diamond is important nal growth sectors in synthetic diamonds (see Slugley because the type categories can be related to the et al., 1987, 1993a and b; Ponalho, 1992). gemological properties that diamonds exhibit. As- In this chart, we also cite some EDXRF chemical grown synthetic yellow diamonds are type Ib, a type analysis results. This method is routinely used at that is very rare in nature; those that are treated at gem-testing laboratories to distinguish natural, treat- high pressure or that are irradiated and heat treated ed, and synthetic gem materials. Our EDXRF data can be predominantly type IaA. Blue synthetic dia- indicate that synthetic diamonds typically contain monds are type Hb (as are most natural blues), where- traces of the flux metals (such as iron or nickel) from as the near-colorless to colorless synthetics studied to which they are grown (see, e.g., the EDXRF spectrum date are usually type Ha. The type categories of corre- in Moses et al., 1993a, p. 185, and the data in Shgley sponding colors of natural diamonds are also listed on et al., 1993a, p. 234, which indicate the presence of Fe the chart. It is important to note, however, that natu- and Ni in both as-grown and treated Russian synthet- ral diamonds referred to as type Ib, unlike synthetics, ic diamonds). They may also contain elements such are rarely "pure" and usually contain some type la as aluminum or titanium that were added to the nitrogen. experimental system to remove nitrogen from the Details of how these gemological properties were growing diamond crystal. Natural diamonds generally documented in both synthetic and natural diamonds do not have trace impurities that can be detected by are briefly presented in the "Key to Information" sec- EDXRF (which cannot detect any of the low-atornic- tion at the bottom of the chart.

Diamond Chart GEMS & GEMOLOGY Winter 1995 Note that the chart does not present information differences in both growth history and impurity con- on natural diamonds that might have a synthetic dia- tents in crystals from one locality to the next. Thus, mond coating placed on them to change their color or there is a greater possibility for exceptions to the possibly their weight. In the course of our research, information on natural diamonds presented in the we arranged to have three natural type la colorless chart than to that given for synthetic diamonds. diamonds coated with a layer of blue, type IIb syn- The chart also includes a number of photographs thetic diamond (Fritsch, 1991; Fritsch and Phelps, and photomicrographs. These pictures were selected 1993).These three stones could be readily recognized to illustrate visual features of synthetic and natural by the uneven deposition of the synthetic diamond diamonds that have the greatest diagnostic value for coating, resulting in irregularities in blue coloration identification purposes. The photographs are refer- (especially along facet junctions), as well as by dis- enced by number (FIG = figure) in the relevant por- tinctive features in their visible and infrared absorp- tions of the chart. tion spectra. To date, we have neither encountered nor heard of any situations where a synthetic dia- HOW THIS INFORMATION mond coating has been applied to a natural diamond WAS ACQUIRED primarily to change its weight or color. Most of the information presented in this chart is based on data collected by GIA researchers over the HOW THE INFORMATION past eight years on approximately 120 synthetic dia- IS ORGANIZED monds. Information on natural diamonds comes Within each column, we present in summary form from our documentation of the gemological proper- only what we believe to be the most commonly seen ties of several thousand diamonds. Information on gemological properties. We should emphasize that not natural and synt!~etic diamonds reported by other all of these diagnostic features arc likely to be found in researchers was compared with our data to confirm each synthetic diamond. However, all synthetic dia- the information shown on the chart. monds we have examined to date display one or more of these features. As stated earlier, the most useful CONCLUSION diagnostic properties include such features as color The accompanying chart summarizes the key charac- zoning, graining, metallic inclusions (microscopicand teristics of synthetic and natural diamonds, empha- submicroscopic), usually causing the synthetic dia- sizing the information that can be obtained by stan- mond to be attracted to a strong magnet (e.g., the dard gem-testing methods, such as magnification, neodymium-iron-boron magnet "wand" developed by ultraviolet fluorescence, and optical absorption spec- Alan Hodglzinson, described in Kammerling et al., tra. Synthetic diamonds currently being marketed 1995a), and uneven luminescence to both W and can be identified positively and reliably on the basis electron radiation. Synthetic diamonds of a particular of the information presented in this chart. color have many similar gemological properties, The chart also provides information derived from although-as noted above-some differences may more advanced testing methods, such as cathodolu- exist between samples from various manufacturers. minescence, EDXRF chemical analysis, and infrared Among natural diamonds, however, the variation in spectroscopy, where this inforn~ationcan provide gemological properties can be much greater because of confirmation of natural or synthetic origin.

REFERENCES Chathain to sell "created" diamonds (1993).New York Diamonds, the International Cerno10,~icalSymposium, Gemological No. 22, Autumn, pp. 44,46. Institute of America, Santa Monica, CA, p. 44. Costan J. (1993)Slow start for Chatham diamonds. Diamond Fritsch E., Scai-ratt K. (1992) Natural-color nonconductivc gray-to- International, No. 26, November/Deceniber, pp. 71-72, 74. blue diamonds. Gems is) Gemology, Vol. 28, No. 1, pp. 35-42. Crowningshielcl R, (1971)Genera Elecliic's cuttable synthetic dia- Fritsch E., Phelps A.W. (1993)Type Db diamond thin fiilms deposit- monds. Gems ed Gemology, Vol. 13, No. 10, pp. 302414. ed onto near-colorless gem diamonds. Diamond and Related Emms E.C. (1994)Synthetic surprises. Retail Jeweler, Vol. 31, No. Materials, Vol. 2, pp. 70-74. 834 (November3), pp. 8-9. Helnier J. (1994) Synthetics-dilemma for Russia. Diamond Fritsch E. (1991) Gemological applications of synthetic diamond International, No, 28, MarchIApril, pp. 55-56. and diamond-like carbon products grown using the low-pres- Henii U., Bank 14. (1993)Gemiiiologische Kurzinforniationcn. sure deposition technique. In AS. Keller, Ed., Proceedings of Zeitscluift fur Deutscl~enGemn~ologischen Gesellscl~aft, Vol.

Diamond Chart GEMS &A GEMOLOGY Winter 1995 263 42, No. 213, p. 66. (1993)De Beers near colorless-to-blueexperimental gem-quality syn- Howard T. (1995) Much ado about man-made diamonds. thetic diamonds. Gems el Gemology, Vol. 29, No. 1, pp. 38-45. American fewehy Manufacturer, Vol. 40, No. 9 (September), Scarratt I<., DLIToit G., Sersen W. (1994)Russian synthetics exam- pp. 22,24, 116. ined. Diamond International, No. 28, MarchIApril, pp. 45-52. Kammerling R.C., Moses T., Fritsch E. (1993)Gem trade lab notes: Shigley J.E., Fritsch E., Stockton C.M., Koivula J.I., Fryer C.W., Faceted yellow synthetic diamond. Gems ei) Gemology, Vol. Kane R.E. (1986)The gemological properties of the Sumitomo 29, No. 4, p. 280. gem-quality synthetic yellow diamonds. Gems a) Gemology, Kammerling R.C., Koivula J.I., Fritsch E. (1995a)Gem news: New Vol. 22, No. 4, pp. 192-208. magnet for gem testing. Gems a) Gemology, Vol. 31, No. 1, p. 69. Shigley J.E., Fritsch E., Stockton C.M., Koivuk J.I., Flyer C.W., Kammerling R.C., Reinitz I.R., Fritsch E. (1995b) Gem trade lab Kane R.E., Hargett D.R., Welch C.W. (1987)Gemological prop- notes: Synthetic diamond suite. Gems a) Gemology, Vol. 31, erties of the De Beers gem-quality synthetic dian~onds.Gems No. 2, pp. 122-12.3. d Gemology, Vol. 23, No, 4, pp. 187-206. Kanda I-I., Lawson S.C. (1995)Growth temperature effects of inipu- Shigley J.E., Fritsch E., Koiwla J.I., Sobolev N.V., Mahovslzy I.Y., rities in HP/HT diamonds. International Diamond Review, Pal'yanov Y. (I993a)The gemological properties of Russian NO. 2, pp. 56-61. gem-quality synthetic yellow diamonds. Gems ei) Gemology, Koivula J.I., Fryer C.W. (1984)Identifying gein-quality synthetic Vol. 29, No. 4, pp. 228-248. diamonds: An update. Gems es) GemoZosy, Vol. 20, No. 3, pp. Shigley J.E., Fritsch E., Rcinitz I. (1993b)Two near-colorless 146-158. General Electric type-Ua synthetic diamond crystals. Gems eJ Moses T.M., Reinitz I., Fritsch E., Shigley J.E. (1993a)Two treated- Gemology, Vol. 29, No. 3, pp. 191-197. color synthetic red diamonds seen in the trade. Gems ei) Shigley J.E., Fritsch E., Koivula J.I., Kammerling R.C. (1995) Gemology, Vol. 29, No. 3, pp. 182-190, Identifying features of synthetic diamonds. Rflpa~~ortDiamond Moses T., Krimmerling R.C., Fritsch E. (1993b) Gem trade lab Report, Vol. 18, No. 20 (June2), pp. 4-5 plus insert supplement, notes: Synthetic yellow diamond crystal. Gems ed Ge~nology, Sosso F. (1995) Some observations on a gem-quality synthetic yel- Vol. 29, No. 3, p. 200. low diamond produced in the region of Vladimir (Russia). Nassau I<. (1993) Are synthctic diamonds from Russia a threat? fourno1of Gemmology, Vol. 24, No. 5, pp. 363468. Rapaport Diamond Report, Vol. 16, No. 35 (November 5), pp. Sunagawa I., Ed. (1984) Materials Science of the Earth's Interior, 29,3 1-32, Terra Scientific Publishing Co., Tokyo. Ponaldo J. (1992)Cathodolu~iiinesccnce (CL) and CL spectra of De Sunagawa 1. (1995) The distinction of natural from synthetic dia- Beers' experimental synthetic diamonds. Journal of mond. Jownal 01 Gemmology, Vol. 24, No. 7, pp. 485-499. Gemmology, Vol. 23, No. I, pp. 3-1 7, van Royen J. (1994) Fancy colour di.-imotids. Antwerp Facets, pp. Rooney M-L.T., Welbourn C.M., Shigley J.E., Fritsch E., Reinitz I. 41-49.

ADDITIONAL READING Collins A.T. (1991) Optical centres in synthetic diamonds-a Vol. 29, No. 3, pp. 207-208. review. In R. Messier, J.T. Glass, J.E. Butler, R. Roy, Eds., New Koivula J.I., Kammerling R.C., Fritsch E. (1993) Gem news: Diamond Science and Technology, Materials Research Sumitomo Electric synthesizes high-purity diamonds. Gems ei) Society, Pittsburgh, pp. 659470. Gemology, Vol. 29, No. 3, p. 208. Crowningshicld R. (1990) Gem trade lab notes: Diamond, fancy Lidclicoat R.T. Jr. (1986)The ultimate synthetic: A jewelry-quality intense yellow. Gems eJ Gen~ology,Vol. 26, No. 4, pp. 295-296. diamond. Gems eJ Gemology, Vol. 22, No. 4, p. 191. Field J.E. (1992) The Properties of Natural and Synthetic Nassau K. (1993) Five different kinds of synthctic diamond. Diamonds. Academic Press, London. Canadian Gemmologisi, Vol. 14, No. 1, pp. 8-12. Fritsch E., Shigley J.E. (1993)Thc separation of natural from syn- Nassau K., Nassau J. (1978)The history and present status of syn- thetic gem-quality diamonds on the basis of crystal growth cri- thetic diamond, Parts 1 and U. Lapidmy fouinal, Vol. 32, Nos. 1 teria. Journal of Crystal Growth, Vol. 128, pp. 425-428. and 2, pp. 76-96 and 490-508. Fryer C.W. (1987)Gem trade lab notes: Synthetic diamond. Gems Recker K. (1984)Synthetischc Diamanten. Zeitschiift da Deutschm ei) Gemology, Vol. 23, No, 1, p. 44, Gemmologischen Geselkchaft, Vol. 33, No. 112, pp. 5-34. Giinthcr B. (1995) Synthetische Diamanten und Ihrc Erkeru-iung. Rossman G., Kirschvinlz J.L. (19841 Magnetic properties of gem- Cold und S'ilber, No. 2, pp. 46-48, quality synthetic diamonds. Gems eJ Cen~ology,Vol. 20, No. Koivula J.I., Kammerling R.C. (1990) Gem news: De Beers 3, pp. 163-166. announces world's largest synthetic diamond crystal. Gems ei) Scarratt I<. (1987)Notes from the laboratory-11. Journal of Gemology, Vol. 26, No. 4, p. 300, GemmohgyJol. 20, No. 718, pp. 406-409. Koivula J.I., Kammerkng R.C. (1991)Gem news: G.E. synthesizes Shigley J.E., Fritsch E., Stockton C.M., Koivula J.I., Flyer C.W., large carbon-13 diamonds. Gems ei) Gemology, Vol. 27, No. 4, Kane R.E. (1987)Les diamants synthitiques Sumitomo. Revue pp. 254-255. de Gemmologie a.fg., No. 92, pp. 10-14. Koivula J.I., Kamnierling R.C. (1991)Gem news: Gem-quality syn- Shigley J.E., Fritsch E., Reinitz I., Moon M. (1992) An update on thetic diamonds from the USSR. Gems ei) Gemology, Vol. 27, Sumitoino gem-quality synthetic diamonds. Gems a) No, 1, p. 46. Gemology, Vol. 28, No. 2, pp. 116-122. Koivula J.I., Kamiiierling R.C., Fritsch E. (1992) Gem news: An Shigley J.E., Fritsch E., Kammerhng R.C., Koivula J.I., Moses T.M. update on diamond research. Gems &> Gemology, Vol. 28, No. (1993) Identifying gem-quality synthetic diamonds. Rapaport 4, pp. 268-269. Diamond Report, Vol. 16, No. 26 (August 6), pp. 10-13. Koivula J.I., Kainincrling R.C., Fritsch E. (1993) Gem news: De Shigley J.E., Fritsch E., Kanimerling R.C., Moses T.M. (1993) Becrs now marketing high-quality, high-pressure synthetic dia- Identifying faceted gem-quality synthetic diamonds. New York mond products. Gems m) Gemologjl, Vol. 29, No. 2, p. 130. Diamonds, No. 22, Autumn, pp. 48-54. Koivula J.I., Kammerling R.C., Fritsch E. (1993) Gem news: GIA Walzatsuki M. (1984) Synthesis researches of diamond. In I. says Russian gem-quality synthetic diamonds examined to Sunagawa, Ed., Materials Science of the Earth's Interior, Terra date can be identified by standard tests. Gems ed Gemology, Scientific P~~blishingCo., Tokyo, pp. 35 1474.

264 Diamond Chart GEMS & GEMOLOGY Winter 1995 BACK ISSUES OF Spring 1987 Fall 1991 Modern" Jewelry; Retro to Abstract Rubies and Fancy Sapphires from Vietnam Infrared Spectroscopy in Gem Identification New Rubies from Morogoro, Tanzania A Study of the General Electric Synthetic Jadeite Bohemian Garnet-Today Iridescent Orthoamphibole from Greenland Winter 1991 Summer 1987 Marine Mining of Diamonds off Southern Africa Gemstone Durability; Design to Display Sunstone Labradorite from the Ponderosa Mine Wessels Mine Sugilite Nontraditional Gemstone Cutting Three Notable Fancy-Color Diamonds Nontransparent "CZ" from Russia The Separation of Natural from Synthetic Limited quantities of these issues are still avai Spring 1992 Emeralds by Infrared Spectroscopy Gem-Quality Green Zoisite The Rutilated Topaz Misnomer Kilbourne Hole Peridot Fall 1987 Fluid Inclusion Study of Querflaro Opal An Update on Color in Gems. Part I Natural-Color Nonconductive Gray-to-Blue Diamonds The Lennix Synthetic Emerald Peridot as an Interplanetary Gemstone Kyocera Corp. Products that Show Play-of-Color Summer 1992 Man-Made Jewelry Malachite Gem Wealth of Tanzania Inamori Synthetic Cat's-Eye Alexandrite Gamma-Ray Spectroscopy and Radioactivity Winter 1987 Dyed Natural Corundum as a Ruby Imitation The De Beers Gem-Quality Synthetic Diamonds An Update on Sumitomo Synthetic Diamonds Queen Conch "Pearls" The Seven Types of Yellow Sapphire and Their Fall 1992 Stability to Light Ruby and Sapphire Mining in Mogok Bleached and Polymer-Impregnated Jadeite Summer 1988 Radiation-Induced Yellow-Green in Garnet The Diamond Deposits of Kalimantan, Borneo An Update on Color in Gems. Part 3 Winter 1992 Pastel Pyropes Determining the Gold Content of Jewelry Metals Three-Phase Inclusions in Sapphires from Sri Lanka Diamond Sources and Production Sapphires from Changle, China Fall 1988 An Economic Review of Diamonds Spring 1993 The Sapphires of Penglai, Hainan Island, China Queensland Boulder Opal Iridescent Orthoamphibole from Wyoming Update on Diffusion-Treated Corundum: Detection ol Treatment in Two Green Diamonds Red and Other Colors A New Gem Beryl Locality: LuumSki, Finland Winter 1988 ,. . Gemstone Irradiation and Radioactivity De Beers Near Colorless-to-Blue Experimental Amethyst from Brazil Gem-Quality Synthetic Diamonds Opal from Opal Butte, Oregon Summer 1993 Kyocera's Synthetic Star Ruby Flux-Grown Synthetic Red and Blue Spinels Spring 1989 from Russia The Sinkankas Library Emeralds and Green Beryls of Upper Egypt The Gujar Killi Emerald Deposit Reactor-Irradiated Green Topaz Beryl Gem Nodules from the Bananal Mine Fall 1993 "Opalite:" Plastic Imitation Opal Jewels of the Edwardians Summer 1989 A Guide Map to the Gem Deposits of Sri Lanka Filled Diamonds Two Treated-Color Synthetic Red Diamonds Synthetic Diamond Thin Films Two Near-Colorless General Electric Type lla 'all 1994 Grading the Hope Diamond Synthetic Diamond Crystals Diamonds with Color-Zoned Pavilions Wlnter 1993 Fall 1989 Russian Gem-Quality Synthetic Yellow Diamonds Polynesian Black Pearls Heat Treating Rock Creek (Montana) Sapphires The Capoeirana Emerald Deposit Garnets from Allay, China Brazil-Twinned Synthetic Quartz Spring 1994 Thermal Alteration of Inclusions in Rutilated Topaz The Anahf Ametrine Mine, Bolivia Chicken-Blood Stone from China Indaia Sapphire Deposits of Minas Gerais, Brazil Wlnter 1989 Flux-Induced Fingerprints in Synthetic Ruby Emeralds"' T----~res of the Atocha Summer 1994 Zircon frc nge, Australia Synthetic Rubies by Douros Blue fftM Emeralds from the Mananjary Region, Reflectanc~ -r.3roscopy in Gemology Madagascar; Internal Features Mildly Ra i . Zhireslones Synthetic Forsterite and Synthetic Peridot Spring 1990 Complete your back issues of Update on Mining Rubies and Fancy Sapphires in Gem Localities of the 1980s Gems & Gemology NOW! Northern Vietnam Gemstone Enhancement and Its Detection Fall 1994 Synthetic Gem Materials of the 1980s Single Issues" $ 9.95 ea. U.S. $ 14.00 ea. elsewhere Filled Diamonds; Identification and Durability New Technologies of the 80s Complete Volumes:' Inclusions of Native Copper and Tenorite in Winter 1990 1986,1987,1991, Cuprian-Elbaite Tourmaline, Paralba, Brazil The Dresden Green Diamond 1992,1993,1994 $ 36.00 ea. vol. U.S. $ 45.00 ea. vol. elsewhere Winter 1994 Identification of Kashmir Sapphires Three-year set $ 99.00 U.S. $125.00 elsewhere Color Grading of Colored Diamonds in the GIA A Suite of Black Diamond Jewelry Five-year set $160.00 U.S. $200,00 elsewhere Gem Trade Laboratory Emeraldolite Ruby and Sapphire from the Ural Mountains, Russia '10¡,. discouni lor GIA Annual Fund donofs a1 Ihe Booster's Circle level and above. Spring 1991 I Gem Corundum in Alkali Basalt Age, Origin, and Emplacement of Diamonds Emeralds of Panjshir Valley, Afghanistan TO ORDER: Call toll free (800) 421-7250, ent. 202 or Some issues from 1984-1986 are also available Summer 1991 (31 01 829-2981, ext. 202 Please call the Subscriptions Office for details. Fracture Filling of Emeralds: Opticon and "Oils" FAX (31 0) 453-4478 OR WRITE; BAG Subsctiptlons 6IA Supplies of all issues are limited. Emeralds from the Ural Mountains, USSR 1660 Stewart Street, Santa Monica, CA 90404 USA Treated Andamooka Matrix Opal ORDER NOW! Editors Robert C. Kammerling and C.W. Fryer GM Gem Trade Laboratory, West Coast

Contributing Editors GIA Gem Trade Laboratory, East Coast G. Robert Crowningshield Thomas Moses Ilene Reinitz Karin Hurwit I GM Gem Trade Laboratory, West Coast LAB NOTES Mary L. Johnson * Shane F, McClure Cheryl Y. Wenlzell

DIAMOND nlents showed up on the EDXRF the lo-Ii range); one large feather tra- Fancy Black, with Iron (which cannot detect carbon and versed the table, and others were pre- other low-atomic-number elements). sent. We were surprised to find blue One technique that we sometimes Thus, the presence of iron in a and orange flash colors associated apply to diamonds suspected of being diamond does not by itself prove that with the larger feathers (figure 2). synthetic is energy-dispersive X-ray the stone is synthetic. However, this Even more surprising was that fluorescence spectroscopy (EDXRF). stone was not attracted to a powerful EDXRF spectroscopy, which we used Because iron (Fe) and nickel (Ni) are hand-held magnet, despite its detectable to confirm the presence of the filling used in the catalyst for synthetic dia- iron content; the iron-nickel flux substance, showed that the filler con- mond formation, these elements are found in synthetic diamonds is strong- tained thallium (Tl)in addition to the found in the metallic flux inclusions ly magnetic. Mu more typical Pb and Br that we have in many synthetic diamonds and are previously documented in filled dia- detectable by EDXRF even if no flux monds. Some early fillers had been inclusions can be identified. However. Fracture-Filled rumored to contain thallium, a heavy the mere presence of Fe and/or Ni is with Unusual Material element that contributes to high not proof of synthetic origin. Although we have known of fracture- refractive indices in glass, but is haz- Last summer, the West Coast filling as a diamond treatment since ardous to work with because of its laboratory received a 9.61 ct semi- the mid-1980s, only recently has this extreme toxicity. It is possible that translucent, marquise-cut black dia- treatment received widespread pub- this toxicity is why thallium has not mond for origin-of-color determina- licity. Consequently, some stones been found in more recent filling inate- tion. Natural-color black diamonds that were treated in the 1980s may rials studied by the GIA Gem Trade typically owe their color to nuiner- have gone through several owners by Laboratory [see R. C. Karnmerling et ous black inclusions. Magnification now. Even if treatment had been dis- al., "An Update on Filled Diamonds: revealed that this heavily included closed originally, such disclosure Identification and Durability," Fall stone was no exception: The black might not have been passed down to 1994, pp. 142-1 77, as well as the above- inclusions were arranged in bands, subsequent owners. As another com- mentioned references). Therefore, we with brown and near-colorless bands plicating factor, the body color of the suspect that this stone may have also present. In addition, large frac- stone can obscure the diagnostic been one of the earlier filled diamonds. tures in the stone showed brown flash colors in fracture-filled dia- MLJ, SFM, and Dino DeGhionno staining. Although a11 EDXRF spec- monds, making recognition of this -- trum was not needed to determine diamond treatment more difficult in cause of color, we ran one to see if it fancy-color stones (see, e.g., "A Visual JADEITE JADE would show anything about the Guide to the Identification of Filled inclusions. It revealed that iron was Diamonds," by S. F. McClure and Extremely Thin Carving present in the stone, probably as the R. C. Karnmerling, Gems ?t> Gemology, A Fall 1995 Lab Note (pp. 199-201) brown iron-oxide stains in the large Summer 1995, pp. 114-1 19; as well described two "carvings" that the fractures. Another possible source is as the Summer 1991 [p. 1091 and Fall West Coast lab determined were real- residue from the polishing wheel. 1995 [pp. 198-1991 Lab Notes). ly assemblages. They consisted of Such build-up is particularly coin- In September 1995, the West mon in black diamonds, because they Coast laboratory received a 1.07 ct contain so many fractures and cavi- yellowish orange cut-cornered rectan- Editor's note: The initialsat the end of each item identity ties. The black inclusions that gave gular modified brilliant (figure 1) for the contributing editw(s) who providedthat item. the stone its color were probably an origin of color report. The appar- Gems & Gemology, Vol. 31, No. 4, pp. 266-273 graphite, since no additional ele- ent clarity of the stone was low (in 0 1996 Gemological Institute of America

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 was con~pletelyremoved, further infrared spectroscopy testing gave no indication of polynler. This instance should serve as a caution to gemologists: Examine jadeite pieces carefully for evidence of repairs, setting cements, and the like. Otherwise, an "innocent" piece of jade might be wrongfully identified as "B" (plastic-impregnated)jade. GRC

Figure 1. The presence of thalli- Figure 2. The yellowish orange um in the substance with body color of the diamond Impregnated SYNTHETIC OPAL which this 1.07 ct diamond was shown in figure 1 almost The Summer 1995 Gem News col- filled suggests that it was treat- masked the orange darkfield umn contains a preliminary report on ed some time ago, possibly in flash color; even the blue bnght- plastic-impregnated synthetic opal the mid-1980s. field color seems subdued. being produced by the Kyocera Magnified 25x. Corporation of Kyoto, Japan (pp. 137-139). When samples were first thin, hollowed-out shells of natural- obtained for examination-at the color green jadeite jade that were sequent discussion with the client Tucson gem shows in February filled with a transparent, colorless we learned that the carving, which 1995-the material was reportedly plastic. In early fall 1995, we received had been mounted in a pendant, was .only being test marketed in Korea for identification what initially appeared damaged while being transported in a and Japan. to be a related item: a translucent, suitcase. Therefore, it is possible that Shortly after the Gem News mottled green-and-white piece of a the carving origin~llywas just a thin entry appeared, the West Coast lab carving (figure 3). Standard gem-test- shell of jadeite, Without the added received for identification a 3.42 ct ing methods revealed a 1.66 spot R.I., durability provided by a plastic filler, piece of partially polished, translu- an aggregate polariscope reaction, and the item would have been quite sus- cent, black rough with play-of-color. a 437 nm absorption line, which con- ceptible to breakage when pressure firmed that it was jadeite jade. Fine was applied to its surface. absorption lines in the red portion of RCK andSFM Figure 3. This jadeite carving the spectrum proved that the green (26.55 x 18.00mm) is extremely color was natural. The item was thin, only about 0.13 mm in A Testing Precaution unusual not only for its extreme some areas, as shown by the thinness, but also because it had been Submitted to the East Coast laborato- chip at the bottom left, carved so that raised areas on one ry for examination, the ring-mounted side complimented recessed areas on cabochon in figure 4 was determined the opposite side. We speculated that to be natural-color jadeite jade by stan- this might have been done to main- dard gem-testing methods. However, tain a uniform thickness-and resul- testing for plastic impregnation by tant uniform depth of color-across infrared spectroscopy-routinely the entire item. During the examina- done on all jadeite submitted to the tion, we also saw a colorless foreign laboratory-was inconclusive. material on small scattered areas of We therefore asked the client to the surface (which we noted in the have the stone removed from the set- report's conclusion; possibly this ting for further testing. Once the material was the glue used in the set- stone was out of the setting, we saw ting process). that it was really a half bead, with At first we thought that the item the remnants of the drill hole clearly might be the top layer of an assem- visible along its base. We also noted blage, similar to the assemblages that the half bead had been cemented described in the previously men- into the setting; the adhesive fluoresced tioned Fall 1995 Lab Note (but minus weakly to long-wave UV radiation (fig- the plastic filling). However, in a sub- ure 5). When the polymer cement

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 and Occurrence of Green Quartz" Gems es) Gemology, Spring 1982, pp. 39-42]. Citrine is also found at this locality. Recently, synthetic quartz from Russia has become available in many colors, including green; syn- thetic green quartz, misrepresented as natural material from Brazil, was discussed in a Winter 1992 Lab Note (p.265). In May 1995, the West Coast lab received for identification a bicol- ored-yellowish green and orangy yellow-emerald cut (figure 6). Most Figure 4. The material used to Figure 5. Once the stone in fig- of the gemological properties were cement this natural-color jadeite ure 4 was taken out of its set- typical for quartz, but they were not "cabochon" (7.55 x 7.63 x 8.45 ting, we realized that the "cabo- useful in determining whether this mm) to its setting produced chon" was actually half a bead. stone was natural, treated, or syn- aznbiguo~isreadings in the Note the weak fluoresence of the thetic. Among the properties that stone's infrared spectrum. adhesive to Iong-wave UV. pointed to synthetic origin were: color zoning in planes perpendicular to the optic axis (not known to occur in natural quartz), lack of twinning Because the piece closely resembled plastic-impregnated synthetic opals, (twinning was seen in three natural (in body color, diaphaneity, and play- we examined the specimen with control] "prasiolitesl' examined), and of-color pattern) some of the treated Fourier Transform infrared (FTIR) scattered "breadcrumb" inclusions synthetic opals we had recently exam- spectroscopy. Opal is opaque to the [much more common in synthetic ined, our suspicions were immediate- infrared below 4000 cm-1; however, than in natural amethyst, which is ly aroused. this spectrum showed several absorp- what we would expect this stone to An R.I. reading taken from the tions between 6000 and 4000 cm-1, have originated as if it was natural side of the piece gave a value of 1.44. which are not seen in natural opal quartz). However, the top gave a reading of (but were seen in the Kyocera However, EDXRF, UV-visible, 1.50, unusually high for either natu- material] and which we attribute to and infrared spectroscopy also ral or synthetic opal. We tentatively an impregnating polymer. demonstrated features unlike those attributed this to surface "overflow" On the basis of all of these results, typical for natural citrine or green of the impregnating substance (see and following CIA Gem Trade quartz, including: significant potassi- below). Specific gravity, determined Laboratory policy of disclosing any um [seen with EDXRF]; sharp peaks hydrostatically, was 1.82, too low for treatments detected, the specimen in the UV-visible suectra of both untreated synthetic opal, but only was identified as impregnated syn- green and yellow regions at about slightly lower than the lowest values thetic opal. RCK and SFM 345, 398, 420, 458, and 487 nm (may that we had obtained on the Kyocera be caused by C&); and a "hump" in treated synthetic opal. the infrared absorption spectrum at The faint orange fluorescence to SYNTHETIC QUARTZ, about 3000 cm-1. This combination short-wave ultraviolet radiation, with Green and Yellow Bicolor of features proved that this material no reaction to long-wave UV, was was indeed synthetic quartz. consistent with our observations on Green quartz, sometin~esknown by ML], SFM, RCK, and Kyocera test samples with a similar the trade name "prasiolite," is a chal- Emmanuel Fritsch body color. Magnification revealed lenging material to identify. In the the "lizard-skin" pattern typical of past, much of the green quartz on the synthetic opal and a pronounced market was heat-treated amethyst, ROCK Resembling Jadeite columnar structure perpendicular to the so-called "greened amethyst" this pattern. With magnification, we [see, e.g., Summer 1983 Lab Notes, p. The opaque variegated green-and-white also saw that the surface that gave 116). Natural green quartz occurs in cabochon (15.50 x 7.00 mm] in figure the higher R.I. value had a thin, at least one area in California where 7 was cemented to a snuff-bottle transparent, colorless coating. amethyst was subjected to natural stopper. According to the client who

Because of the unusually low heating-. (volcanic activity;, . see T. submitted it to the East Coast lab for S.G. and our recent experience with Paradise, "The Natural Formation identification, this material closely

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 resembled that of die bottle to which it belonged. Although a spot reading on the refractometer was within the jadeite range, there was a noticeable birefrin gence-in fact, a "carbonate blink' -from 1.50 to 1.65. However, no effervescence occurred when a minute drop of dilute HCl acid was placed in an inconspicuous spot on its surface. Effervescence would be expected if the cabochon were either of the carbonate minerals calcite or aragonite. As our testing at this point was inconclusive, we performed X-ray diffraction analysis. This revealed that the cabochon was a rock consist- ing principally of dolomite, a little quartz, and other, unidentified, inin erals. Dolomite is one of the few car bonate minerals that do not effer vesce (unless powdered) to a weak HCl acid solution. To determine what the unidentified minerals were, petrographic testing would have been required. We informed the client of Figure 6. Testing revealed that this 8.47 ct green-and-yellow bicolor is a this in the report's conclusion. synthetic quartz. GR C

ruby, and internal features were = RUBY 1.769, no 1.778. EDXRF chemical indicative of heat treatment. We were analysis by GIA Research revealed an With Atypically High R.I.'s surprised, however, by the unusually unusually high chromium content: The article "Update on Diffusion- high refractometer readings: n,- = 2.77 wt.% Cr203. Treated Corundum: Red and Other In "Rubies from Mong Hsu" Colors" (S. F. McClure et al., Gems (Gems o) Gemology, Spring 1995, pp. d Gemology, Spring 1993, pp. 16-28) 2-26), authors Peretti et al. note that focused on treated stones in purplish Figure 7. This cabochon, which rubies from this relatively new pink, reddish purple to purplish red, formed the top of a snuff bottle Myanmar locality have unusually and orangy red hues. One feature doc- stopper, consists of dolomite, high chromium contents (as high as uniden- umented in many of these sample some quartz, and other, 2.86 wt.% Cr203 in one stone they stones, in contrast to documented tified, minerals. analyzed] and, furthern~ore,may blue diffusion-treated sapphires, was show high R.I. values (nE= 1.760-1.770, die presence of unusually high refrac- no = 1.768-1.780). The 1.19 ct ruby tive indices. The authors speculated we tested had a chromium content that this was due to the high chromi- and R.I. values that fall within the um content in the diffused surface upper limits of those reported in that layer, and they made reference to a article, and its other internal charac- report in the literature mentioning teristics were consistent with those high R.I. readings from high-chromi- reported for Mong Hsu stones. The urn-content rubies and orange sap- above-referenced article by Peretti et phires from Malawi. al. also pointed out that heat-treated Recently, the West Coast lab was Mong Hsu rubies may contain glass- asked to identify a 1.19 ct red oval filled fissures, a feature that has mixed cut. Standard gemological test- resulted in their being misidentified ing identified the stone as natural as flux-grown synthetics. The high

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 seen recently in the East Coast lab a desk-model spectroscope, which had a nea--colorless zone at die base. At eniploys intense transmitted illumi- first glance, it looked very much as if it nation, or when we use similar light- was an area where dye had not "taken." ing to examine a stone with a Routine examination with a hand spec- Chelsea color filter. Gem materials troscope revealed a typical ruby that may exhibit this feature include chromium spectrum, with no evi- natural and synthetic emerald, natu- dence of dye. Microscopic examination ral and synthetic ruby, synthetic not only confinned that the stone was alexandrite, synthetic blue spinel, natural with no dye, but it also showed and natural "cobalt" blue spinel. In that it had not been heat treated. all of these examples, the lumines- An attractive 9.57 ct natural star cence is an evenly distributed red. An ruby with another anomaly was also seen in the East Coast lab. Not visi- Figure 8. A nearly colorless area ble in the face-up view in figure 9 is can be seen at the base of this an area on the bottom and part of one natural ruby cabochon (about side that contained a soft, epoxy-like 16.5 x 11.7 x 8.0inin). filling (figure 10). If the stone was carefully mounted, this area would probably not be seen and, in any event, it was undoubtedly deemed R.I. values of some Mong Hsu rubies preferable in appearance to the large may help separate then1 from flux- cavity that it filled. Although grown synthetics (which typically ~lglass"-filledcavities in ruby are not fall in the range 1.762-1.770). uncommon, this was one of the few Figzire 11. Red 11iinii1escenceto This was the first of these high- instances we have encountered of a intense transmitted light is con- R.I. rubies seen in the West Coast soft, epoxy-like filling in this gem fined to distinct bands, such as laboratory. Given what we know material. GRC the one shown here, in this about Mong HSLIrubies and the 19.45 ct blue sapphire. quantities that are currently entering Magnified 20x. the niarketplace, as well as the occur- SAPPHIRE, with Zoned rence of Malawi rubies with high Transmission Luminescence refractive index readings, we suspect that we will be seeing more high-R.I. Some gem materials luminesce when exception is the green transmission stones in the future. high-intensity visible light is trans- luminescence of some dian~onds, RCK and SFM mitted through them, a feature which normally occurs in fairly dis- gemologists call "transmission lumi- tinct planes or zones. Two Stones with Unusual Features nescence." In practice, we usually see In early 1995, the West Coast lab A ring-set cabochon ruby (figure 8) this during routine gem testing with received for identification a 19.45 ct transparent blue mixed cushion cut. Routine gem testing identified the stone as a natural sapphire of natural Figure 9. This 9.57 ct star ruby Figure 10. In this side view of color (that is, not heat treated or oth- (about 14.05 x 9 x 7 mm) shows the star ruby shown in figure 9, erwise enhanced]. When we exam- no evidence of cavity filling a large cavity with an epoxy-lilze ined this stone with a desk-model when observed face-LIP. filling is evident. spectroscope, we were surprised to see a strong red luminescence that appeared to be unevenly distributed. When we used magnification in con- junction with a fiber-optic light source, it became clear that the lumi- nescence was confined to distinct bands (figure 11). We then performed three EDXRF chemical analyses, with the stone at different orienta- tions to the X-ray beam so we could measure different areas. One analysis

270 Gem Trade Lab Noies GEMS & GEMOLOGY Winter 1995 Figure 12. After only about three i71in1ites' exposure to short-wave UV radiation during testing, this 4.57 ct near-colorless synthetic sapphire (left) turned brownish yellow (right).

revealed the presence of chron~i~~in,Lanlza and the yellow component of nification in conjunction with short- to whichwe attribute the visible- f'padparadscl~affsapphire). In other wave UV radiation (see, e.g., "Synthetic light luminescence. We surmise that such sapphires, the color will fade on Sapphire, Another Striae-Resolution the chromium is unevenly distribut- exposure to light. All such yellow Technique," Winter 1994 Lab Notes, ed in the stone, with the greater con- color is faded by heat. For example, p. 270), we used this method to centrations in those zones that show experimenting with synthetic sap- examine the stone. We successfully the unusual luminescence. RCK phire, one of the editors has had a resolved curved striae, proving that it deep. yellow, induced in colorless syn- was a synthetic sapphire. thetic sapphire- - and a pinkish orange- However, we were not prepared SYNTHETIC SAPPHIRE, produced in synthetic pink sapphire for the appearance of the sample with Color Changed by by exposure to radiation in a gamma when it was removed from the micro- UV Radiation cell. In both situations, it was found scope's stage after the approximately that the yellow color could be removed three-minu te examination: It had Laboratory irradiation has been used by gentle heating in the flame of an turned a medium brownish yellow to change or develop color in many alcohol lamp. (figure 12, right). Approximately six gem materials. Examples include the In summer 1995, the West Coast hours' exposure in a solar simulator development of yellow in beryl, pinli- lab received for identification a 4.57 removed most of the induced color, to-red in tourmaline, blue in topaz, ct transparent, near-colorless emerald but the synthetic sapphire was ulti- brown (the "smoky" color) in quartz, cut, measuring 10.00 x 7.98 x 5.59 mately returned to its original, near- and various colors in diamond. (For mm (figure 12, left). Gemological colorless condition only by a few more information, see K. Nassau's testing revealed refractive indices of minutes of gentle heating in the comprehensive Gemstone Enhance- 1.760-1.768, a birefringence of 0.008, flame of an alcohol lamp. This is the ment, 2nd ed., 1994, Butterworth/ and a uniaxial negative optic charac- first instance we have encountered in Heinemann, Oxford, England, and C. ter-properties consistent with both which a yellow color was induced in E. Ashbaughls "Gemstone Irradiation natural and synthetic corundum. corundum by such a relatively weak and Radioactivity," Gems o) Gem- Magnification with various lighting dosage of radiation. ology, Winter 1988, pp. 196-213.) techniques, including darkfield and RCK and SFM Radiation also causes yellow in briehtfield, failed to reveal any incl~i- corundum, but apparently more than siok or growth structures that could one type of color center can be pro- be used to determine whether the Magnetic SERPENTINE duced. Some radiation-induced vel- stone was natural or synthetic. Because low is stable to light- (e.g.,. -. natural- we have had some success in resolv- Many fine-grained translucent green color yellow sapphires from Sri ing curved growth striae using mag- materials may resemble jade-espe-

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 ble. All these properties were consis- Two features of this natural spinel tent with those of serpentine. were noteworthy: its color, which Our curiosity was piqued, how- changed from violetish blue (in fluo- ever, by the black inclusions. Polishing rescent light] to purple (in incandes- of the piece had left a hackly (as if cut cent light), and its needle-like inclu- with a dull hacksaw) fracture exposed sions (figure 14). These inclusions- on some of these inclusions (figure actually long, thin flat plates- 13). Using low-angle reflected illuini- formed in oriented aggregates in at nation, we saw neither a white sur- least four different directions. On the face (as would be the case with a tita- basis of their appearance, GIA GTL's nium oxide or ilmenite] nor a brown chief research gemologist John I. surface (as with hematite or pyrite). Koivula suggested that these plates Attempts to rub the black material might be exsol~itionlamellae (flat off on a piece of paper were unsuccess- sheets) of hogbomite, [Mg,Fe^jZ- ful, which indicates that it was not (Al,Ti]cOlo,similar to those reported graphite. However, the fact that the by I<. Schmetzer and A. Berger piece was attracted to a hand-held ("Lamellar Iron-Free Hogbomite-24R magnet suggested that the inclusions from Tanzania," Neues Jahrbuch fir Figure 13. There were enough were magnetite, a member of the Mineralogie Monatshefte, 1990, No. 9, magnetite inclusions in this ser- spinel mineral group. This identifica- pp. 401-412, and "Lamellar Inclusions pentine to attract the material tion was confirmed by X-ray powder in Spinels from Morogoro Area, to a magnet. Magnified lox. diffraction analysis of a small scrap- Tanzania," Journal of Gemmology, ing taken from an exposed inclusion. Vol. 23, No. 2, 1992, pp. 93-94). MLI Hoebomite- comes out of solu- cially nephrite jade-at first glance. tion in spinel as the crystal cools In August 1995, a semi-translucent, from high temperatures. According partially polished, green-and-black SPINEL, with to Schmetzer and Berger, it has only piece of rough material was submit- Hogbomite(?)Inclusions been seen in gem spinels from the ted to the West Coast laboratory for Morogoro area of Tanzania, although In February 1995, the West Coast lab identification. Aggregate gem materi- it is found in rock-forming spinels received a 21.38 ct (19.24 x 14.78 x als such as rocks often require extra from other areas. Although Tanzanian 9.28 inm) oval mixed-cut stone for identification effort. Some properties hogbomite is rich in titanium, no identification. The stone was singly (such as S.G.) represent averages of titanium was detected in this stone refractive, had a refractive index of the components present, whereas with EDXRF spectroscopy. We sus- 1.718, and was inert to both long- and other properties (such as R.I.) are rep- pect that these exsol~~tionplates are short-wave UV radiation. Its absorp- resentative of individual grains and too small to affect the stone's overall tion spectrum, as seen with a hand- not of the material as a whole. In the chemistry. ML/ case of this rough material, we quiclz- held prism spectroscope, was typical ly eliminated nephrite as a possibili- for dark blue spinel. ty, but more work was required for A TOPAZ Assemblage positive identification. We determined the following Figure 14. The reflective "needles" The assembly of various materials to gemological properties: R.1.-about (actually, thin plates) in this imitate gems has been with us 1.57 (spot); S.G.-2.63; optic charac- 21.38 ct color-change spinel may throughout the centuries, dating back ter-aggregate; fluorescence-mottled, be hozbomite, a mineral related to Minoan and Roman times. with faint chalky blue areas, to long- to spinel. Magnified 15x. Ancient writings such as the fifth wave UV and inert to short-wave. century A.D. Greek Papyrus Weak absorption at 500 nm was visi- Holmiensis, and Natural History by ble through the hand-held spectro- Roman scholar Pliny (23-79 A.D.], scope. With magnification, the mate- have enlightened us on this practice rial appeared soft, revealing a poor (see, for example, the fascinating arti- polish with many fine scratches and cle by K. Nassau, "An Early History rounded edges on small fractures.The of Gemstone Treatments," in Gems material also revealed an aggregate ei) Gemology, Spring 1984, pp. structure and black, eq~iidiinensional 22-33), Doublets and triplets were inclusions. Some brown areas, which very common imitations of such looked like iron staining, were visi- prized gems as ruby and emerald, at

Gem Trade Lab Notes GEMS &. GEMOLOGY Winter 1995 long-wave UV and fhiorcsced faint green to short-wave UV; and its absorp- tion spectrum (as observed with a desk-model prism spectroscope) showed "fuzzy" bands at 530, 580, and 650 nm (the last being the strongest). The stone was also slight- ly radioactive. Magnification revealed an excel- lent illustrative set of inclusions: par- allel zoning, V-shaped inclusions, Figure 15. This 1.48 ct stone Figure 16. Magnification at 20x, skeletal inclusions (typical of low- resembles some Paraiba tournla- with immersion in methylene property zircons), and especially line, but it is in fact a topaz iodide, reveals the separation angular zoning. The angular growth triplet. plane at the girdle of the assem- planes in figure 17 are probably the bled stone in figure 15. first- and second-order prism faces of zircon, J100)and (110).At the time these faces were at the surface of the least until the advent of synthetics. ZIRCON, stone, they were being exposed to The most common assembled stones with Phantom Planes one or more episodes of deposition or G1A GTL has seen in recent years are dissolution (possibilities include the Sometimes, identifications are not opal doublets and triplets, as well as preferential deposition of solids or particularly difficult, but a stone may combinations of naturalJsynthetic trace elements, dissolution of the zir- contain features that are both photo- corundum and naturalJsynthetic con by fluids, or deposition of exotic genic and good teaching examples. spinel. Much less frequently, we have material leading to later dissolution Such was the case with a 9.24 ct also seen asteriated assemblages (see, of the zircon). They appear as lines green oval mixed cut that arrived in for example, the Fall 1993 Lab Notes, because the photo was taken looking the West Coast lab early in 1995. p. 205). parallel to the planes of these faces, Identifying it as zircon was straight- Recently, however, the East forward: Strong doubling of the back that is, down the c-axis. These planes Coast lab encountered a new type of are decorated phantom faces. facets was seen with magnification; assemblage, in a 1.48 ct faceted oval An additional feature of these the R.I. was over-the-limits of the stone (figure 15). The color resembled planes is that they reveal the relative standard gemological refractometer; that of some Paraiba tourmaline (see, growth rate of the two faces. The the S.G. was 4.04 (measured hydro- e.g., the Fall 1989 issue of Gems a) statically); the stone was inert to larger (longer) face ([100]?)grew more Gemology, p. 182, figure 8, second rapidly than the smaller face ([IlO]?), stone from the left). so the larger face became relatively Microscovic examination of the Figure 17. The decorated phan- shorter as crystal growth proceeded stone with immersion revealed that torn planes in this 9.24 ct faceted (from ihc bottom of the photo to the it was actually a triplet, composed of zircon reveal much about its for- top). Although these features can be a near-colorless crown and pavilion motion. Magnified 20x. seen in many zircon samples, they held together by a greenish blue are particularly well represented in cement (figure 16). Refractive indices this stone. MLf read about 1.60 to 1,61 (birefringence of 0.01) on both die crown and pavil- ion. Biaxial optic figures on both Erratum: The 115.56 ct synthetic pieces confirmed that they were col- ruby described in the last Lab Notes orless topaz. section (Fall 1995, p. 203) was not We can only speculate why this produced by Czochralslu pulling, unusual triplet was created. However, but rather by a related proprietary Paraiba tourmaline of fine color and technique. especially in larger sizes has become verv scarce in the market and com- PHOTO CREORS mands high prices; in addition, no Figure 1 was taken by Maha DeMaggio. The phoiomicro- synthetic tourmaline has been pro- graphs in figures 2, 11, 14, and 17are by John I. Koivula. duced commercially as yet. Shane McClure provided li~ures3, 6, 12 (leli and righl), Nicholas DelRe and 13. Nicholas DeIRe supplied the pictures used in lip ures 4,5,7- 10, 15, and 16.

Gem Trade Lab Notes GEMS & GEMOLOGY Winter 1995 GEM -Editors - Robert C, Kammerling, John 1. Koivula, and Mary L. Johnson Contributing Editors Dino DeGhionno, GIA GTL, Santa Monica, California Henry A. Hanni, SSEF, Basel, Switzerland Karl Schmetzer, Petershausen, Germany

THE 25TH INTERNATIONAL GEMMOLOGICAL CONFERENCE

New synthetics and gem localities, gem treatments, impor- tify their individual constituents, and electron microprobe tant jewelry collections, and advanced gemtesting ineth- analysis was conducted to measure the average chemistry ods were among the topics of over 30 presentations at this for each inclusion. October's 25th International Gemmological Conference Thirteen diamonds from Botswana were found to con- (IGC),held in Rayong, Thailand. tain inclusions of carbonates, apatite, a mica mineral, Official delegates from Australia, Belgium, Brazil, quartz, and a low-atomic-n~iinbernoncrystalline phase (a Canada, France, Germany, Hong Kong, India, Israel, Italy, hydrous fluid). All are probably daughter phases of the Japan, the Netherlands, Singapore, Spain, Sri Lanka, trapped potassium-rich parent melt. The internal pressures Switzerland, Thailand, the United Kingdom, and the of the inclusions could be deduced from the shift in quartz United States attended the conference, which was orga- (infrared) absorption bands from their positions at room nized through the Asian Institute of Gemological Sciences, temperature and pressure; the diamonds probably equili- in Bangkok, by AIGS Director Kenneth Scarratt. brated at 40-70 kbar pressure (120-200 kin depth) and Each biennial conference takes place in a different retained pressures of 15-20 kbar in their inclusions. country; every other one is held in Europe. The first IGC, Similar inclusions were found by Dr. Navon and his organized by Professor K. Schlossmacl~erand Dr. E. J. student, Marcus Schrauder, in fibrous diamonds from Gubehn, took place in 1952 in Locarno, Switzerland. Since Zaire, India, Yakutia, and Sierra Leone. All were associated its inception, the purpose of this invitation-only event has with the eclogitic paragenesis of diamonds. The researchers been the exchange of information anlong laboratory gemol- also found fluid inclusions in white cloud-like formations ogists and others engaged in the science of gemology. in some octahedral peridotitic diamonds from Yalzutia. The following entries are synopses of some of the pre- These inclusions also contained water and carbonates, but sentations given at this year's IGC. Also included are reports the solutes differed in composition. on field trips taken in conjunction with the conference. Drs. Navon and Schrauder also discovered another type of fluid-bearing diamond, which contains solid carbon dioxide (Coy;probably derived from carbonates). This type DIAMONDS of diamond probably equilibrated at 70-80 kbar pressure Fluid inclusions in diamonds. How some properties of fluid (200-250 km depth), and still retained a pressure of about inclusions in diamonds are measured-and the types of 50 kbar in the inclusions. Coyrich diamonds have been fluid inclusions that have been seen-were explored in a found in Yakutia and, recently, in the Sloan luinberlite on talk by Dr. Oded Navon, senior lecturer at The Hebrew the Colorado-Wyoming border. University, Jerusalem, Israel. All the inclusions described were s~ibmicronin size Some historical trends in the diamond industry. Dr, A. A. and were found in regions of the studied diamonds that Levinson, of the University of Calgary, Alberta, Canada, have a fibrous texture, including the outer shells of coated reviewed historical trends-and changes in trends-in the diamonds (figure 1).The internal structures of these inclu- diamond industry over the last century. Topics included sions were magnified by means of a transmission electron changes resulting from major new discoveries (such as microscope (TEM),infrared spectroscopy was used to iden- Russia, Botswana, and Australia); changes in the percentage

Gem News GEMS & GEMOLOGY Winter 1995 Hymenuea protera of the Legunzinoseae family, which pro- duced the resin that fossilized to form much of the amber from this region. Magnification revealed a small insect (Thysanoptera, or thrip) that was trapped in the anther's pollen slit along with numerous tiny pollen grains (figure3). Also described was a collection of iolite pebbles (from Sri Lanlia and Madras, India, gathered over 25 years] that contained blue-green inclusions of sapphirine. Mr. Koivula also illustrated a very rare, transparent blue inclusion in a diamond, which he speculated might be kyanite. Also shown was an inclusion pattern resembling ink droplets against a swirled yellow background. The host was a very pale yellow hessonite from a new locality for this gem: Tissan~aharama,Sri Lanka. The inclusions are actually Figure 1. The edge of a densely packed cloud of blue-green spinel octahedra that, because their refractive tiny fluid inclusions is visible in this diamond at index is similar to that of the host, show very low relief. high magnification (4004. Photomicrograph courtesy of Oded Ncivon. Green beryl and emerald from Central Nigeria. Dr. Charles Arps and Hanco Zwaan, from the National Museum of Natural History and the Netherlands Gemmological of production directly controlled by De Beers; economic Laboratory in Leiden, examined 170 pieces of rough and and political factors affecting diamond production (includ- about 20 cut stones from two areas of central Nigeria: one ing periods in which production virtually ceased in some east of Gwantu (southeastern Kaduna State), and the other mining areas); the importance of specific consumer coun- northwest of Nassarawa Eggon (Plateau State). They inves- tries (such as the United States and Japan); changes in jew- tigated these nearly-200 beryls with regard to crystal habit, elry consumption patterns (for instance, the increasing growth features and inclusions, physical constants, color, importance of jewelry other than the diamond engagement and chemical composition. ring); the effect of low-cost Indian cutting on the retail dia- The crystals were recovered by primitive open-cast mond jewelry industry; and the move to develop new retail mining techniques from fissure fillings and pegmatitic n~arketsfor gem dian~onds,particularly in Asia. stringers and veins occurring in the strongly weathered An important upconling change can be anticipated as granitoid basement rock, which consists of migmatites, a result of the potential development of diamond deposits amphibolites, and various gneisses and schists. In many in Canada's Northwest Territories. In about four years, an , , places in central Nigeria, these Precambrian rocks are cut estimated two-to-three million carats (Mct)of diamonds- by Late Precambrian granite intrusions (Older Granite) and about 25% of which are gem-annually should be available granites of Cretaceous age (Younger Granite complexes). to the rough diamond market, which currently consumes a The widespread occurrence of ores (tin)and other minerals total of about 100 Mct of diamonds per year, of which (such as topaz, aquamarine, and tourmaline) is associated about 50 Mct are cuttable. These Canadian diamonds will with the emplacement of these granite complexes (mainly come from several lun~berlitepipes discovered since 1991 the Younger). and owned by BHP (Australia) and Dia Met (Canada). Green beryl and emerald in the Gwant~iand Nassarawa Although details about the quality and size distribution of Eggon deposits are very likely the crystallization products the diamonds have not been formally released, it is general- of berylliunl-, chromium-, and vanadium-bearing ly accepted that the gems "are considered to be of high hydrothermal or pegmatitic solutions that impregnated the quality, comparable to the best stones in the top ten pipes basement rocks near the Younger Granites. Evidently, the in the world" (Dia Met 1994 Annual Report, p. 5). The presence of chromium and vanadium ions in the salty question then arises as to what, if any, effect this quantity brines is explained by the fact that the fluids passed of apparently high-quality gem diamonds will have on the through Cr- and V-bearing mafic/ultramafic "greenstones" diamond industry. present in the basement rock. Many of the rough beryls studied were relatively long COLORED STONES AND and slender hexagonal prisms with strongly etched crystal ORGANIC GEM MATERIALS faces. Some crystals were irregular or broken at both ends, New and unusual inclusions in- amber and other gems. but others had well-developed pyramidal and pinacoidal Gem News co-editor John I. Koivula described 16 new and terminal faces. The nature of the zoning, together with unusual inclusions that he had recently examined. One two- and three-phase inclusions, clearly pointed to crystal- item described, found in a 6.28 ct amber cabochon from the lization in a hydrothermal or pegmatitic envirom~ient.No Dominican Republic (figure 21, was an anther (the pollen- inclusions that would indicate growth of the emeralds in bearing part of a flower stamen) from the extinct tree the n~afic/ultramaficrocks themselves were encountered.

Gem News GEMS & GEMOLOGY Winter 1995 Most of the samples ranged from near-colorlessand pale good. He thanked Rex Harris, the miner of the material, for green to medium-dark bluish green. They displayed marked his generous cooperation. color zoning both parallel and perpendicular to the c-axis. Strong zoning parallel to the c-axis, characterized by a rela- Gem localities in China. Professor Akira Chikayama, of tively narrow colorless flawed rim amd a transparent (yellow- the A. Chkayama Gem Laboratory in Tokyo, Japan, pre- or bluish) green core, is typical for the Nigerian beryl crystals. sented an update on gem localities in China, based on his Twelve faceted stones (1.84 to 28.66 ct) had specific gravities extensive travels there. between 2.672 and 2.686, and refractive indices of 1.560 to Diamonds are found at Wafangdian in Liaoning I ,567 (extraordinary ray) and 1.565 to 1.572 (ordinary ray). Province, Mengyin in Shandong Province, and Y~ianjiangin UV-visible absorption spectra of the samples showed two dif- Hunan Province; rubies at Yuanyang and Yuanjiang in ferent patterns: (pale)green beryls displayed a stronger pres- Yunnan Province; sapphire at Changle in Shandong ence of iron relative to cluomi~im,whereas cl~ron~iumwas Province and Wenchang on Hainan Dao Island; emeralds at more pronounced in the medium-dark stones. These results Yuanyang and Wenshan, Yunnan Province; and aqua- indicated that -good-color emeralds also occur in the Gwantu marines also at Yuanyang, Yunnan Province, and at Altay, and Nassarawa Eggon deposits. Chemical analyses of pale in Xinjiang Uygur Autonomous Region. (Altay also pro- green emerald indicated that, besides chromium and iron, duces almandine garnets, topaz, tourmaline, zircon, ma- vanadium is present as a coloring agent. The calcium, sodi- zonite, and rose quartz.] urn, and potassium contents are very low compared to emer- Peridot is found at Zhangjialcou, Hebei Province, and aids from other deposits. at Beishishan, Jilin Province. Gem materials found else- where in China include: topaz, tourmaline, zircon, garnets Red beryls from Utah. Dr. Frederick Pough, of Reno, Nevada, (pyrope, almandine, and gross~~lar],nephrite, fluorite, gave an overview of red beryls from Utah's Wall Wah quartz varieties (rock crystal, amethyst, rose quartz, tiger's- Mountains. The red beryls are found just to the south and west eye, green jasper, and green, white, and blue quartzite), of the Thomas Mountains in Utah, one of the many north- rhodonite, turquoise, inalachi~e,amazonite, serpentine, south-trending mountain ranges that comprise the Basin and pyrophyllite (some with cinnabar inclusions), lepidolite, Range geologic province of the western United States. dolomite, saussurite, "chrysanthen~umstone," and ore The red beryls in the Wah Wah Mountains are concen- minerals (hemimorplute, sniithsonite, and cinnabar). trated in seams in white rhyolite. They apparently grew in both directions from a central seed plate: Usually crystals Colored stones seen by CISGEM Laboratory. Dr. Mar- appear to have a break through the middle of the stone, gherita Superclu presented examples of identification prob- with the two parts not perfectly aligned. Inclusions are lems recently seen by herself and co-workers at the CIS- plentiful in the cut stones, which usually weigh less than 1 GEM Laboratory (Chamber of Commerce, Milan, Italy). ct; the largest stone faceted to date is about 7 ct. Certain pink freshwater pearls and red coral were Since tiis is a single-source gemstone [mined only in shown to have natural (for the pearls] and stain-induced [for the Wah Wah Mountains) that is a variety of a well-recog- the coral) colors based on the presence or absence of Raman nized gem material (unlike tanzanite at its first introdue- spectral peaks for carotenoids, which cause the pink and tion), Dr. Pough thinks that the marketing economics look red colors in some organic materials.

Figure 3. A closer look at the anther shown in fig- Figure 2. This 6.28 ct cabochon of Dominican we 2 reveals a tiny insect fThysanoptera) trapped amber contains an anther from the extinct tree in the pollen slit. Photomicrograph by John I. Hyinenaea protera. Photo by Maha DeMaggio. Koivula; magnified 15x.

Gem News GEMS & GEMOLOGY Winter 1995 A new rock, promoted as violet jade, does contain jadeite. A Russian hydrothernial synthetic emerald (con- taining Ni and Cu, but not V) that lacked a flame structure was identified on the basis of its FTIR spectrum. Light-yel- low glass "grown" on a white ceramic "rock" contained high levels of Zn and As (it h:id an R.I. of 1.48 and several sizes of included gas bubbles). Last, a hardened epoxy resin in a natural emerald could be distinguished from several other natural and synthetic resins, including unhardened epoxy resin, based on its Raman spectrum.

New gem deposits in Shan State, Myanmar. Northeastern Myanmar is famous for its conuidum deposits, including both the Mogok Stone Tract and the Mong Hsu area in Shan State. While visiting that state's capital, Taunggyi, one of the editors (RCK) learned of another promising %"re4. Thisemerflldc~stfll,aPProxhately 10 corundum deposit from U Tin Haing, professor of geology mm wider is t~~icfllof the colorandsha~eof at Taunggyi University. Professor Hiding reported that the emeralds from fl newfwd i~?southern India. deposit is located about 100 kin (62 miles) northeast of Pllotob~ffl~s~eePflnl~~(1~ Taunggyi. It is reached by walking some 9 k111 (6 miles] northwest from the town of Lai Hka, which takes about one-and-a-half hours. The corundum-primarily pink sap- The dark green stones had slightly different phues-is found with pink-to-red spinels in a marble hori- cllemistries (determined by atomic absorption spec- zon in about the center of a n~etamoi-phicbelt running troscopy) and fluorescence behaviors than their pale green roughly 130 kin north-south by 1.5 km (about one mile) counterparts. One dark green stone contained 0.92 wt.% wide. Sapphires are also found in associated alluvial Cr203, 0.46 wt.% Fe (as FeO), and 0.02 wt.% V203,A pale deposits. Professor Hlaing believes that cor~~nduinmay green stone contained 0.56, 0.03, and 0.03 wt.% of these have been found in the area as early as 1989, but it was not elements, respectively. recognized as a new deposit because the stones were mixed Among the inclusions seen in Sankari emeralds were ill with Mong Hsu material in the Taunggyi gem market. mica (most conlmon), quartz, apatite (figure 5), feldspar, Recently, garnets have been found at Mong Kung, about pyrite, included hexagonal beryl crystals (visible in polarized 35 lull (22 ndes] north-northwest of Lai Hka, at the eastern light), spinel, black rounded crystals with tension cracks, edge of the inetainoiplic belt. Both ruby and spinel have been large needle-like inclusions (possibly tourmaline or amphi- found in an area between the towns of Lang Hko and Mawk bole), and black carbonaceous matter. Two generations of Mai, approximately 28 lun east-southeast of Tauliggyi. fluid inclusions were seen, with some three-phase inclu- sions in negative crystals among the first generation. New emeralds from southern India. A 15-km-long belt of Remarking on the resemblance of these stones to emeralds inicaceous rocks "near the Idappadi and Koi~anap~~ramvil- from Madagascar, Dr. PanjilCar suggested that both deposits lage of Sankari Taluka" in the Salem district, Tamil Nandu may have come from the same (Precambrian to early State, India, is the site of a new find of emeralds, according to Cambrian) metamorphic belt, split in two with the breakup Dr. Jayslvee Panjikar, of the Gei-mnologicalInstitute of India, of the ancient siipercontinent Gondwanaland. Because of Bombay. She and her colleagues exainined 16 samples, rang- this, she thinks that there is a possibility of finding large ing up to 23.05 ct. They found that these Sankari emerald deposits of emeralds and other gemstones in the area. crystals occur as hexagonal prisms (figure 4), with pyramidal faces and sometimes second-orderprism faces. Natural glass: tektites. Dr. Charles Arps, of the National They determined the following gemological properties: Museum of Natural History in Leiden, presented an color-saturated green to "pale whitish green"; pleochro- overview of tektites, their occurrences, morphology, prop- ism-medium to strong, bright green (parallel to the c-axis) erties, identifying characteristics, and uses. and bluish green (perpendicular to the c-axis); S.G. (hydro- He described tektites as relatively small shyblack to static)-2.70 to 2.73; R.1.-1.582 to 1.585 (extraordinary ray), dark brown or green semitransparent natural glass objects, 1.588 to 1.591 (ordinary ray); birefringenceÑ0.006 and spec- with characteristic but variable shapes, symmetry, and sur- tnim with a hand-held type of spectroscope-strong doublet face morphology. Tektites have been found in four "strewn at 680 mil, fine line at 630 nm.With a spectropl~otoineter, fields," or regions: Southeast Asia/Australia, Czechia in they detected Cr^ peaks at 684, 676.8, 629, and 61 1 nm; Central Europe, the Ivory Coast of West Africa, and soutli- Fe^ peaks at 368.8 and 453 m; (possibly i-ron or vanadium] to-southeastern North America. Although several theories peaks at 504, 530, and 568 mil; and, in darker stones, ad&- have been proposed for the formation of tektites, most geo- tional peaks between 400 and 500 nm. chemical evidence is consistent with their origin as the

Gem News GEMS & GEMOLOGY Winter 1995 Jade market in Mandalay. Although jadeite has been found in a number of countries, including Guatemala and Russia, the major commercid source of this important gem mate- rial is Myanmar (Burma). The main inining area in Upper Burma is situated between Hpalzan and Tawinaw, near the Um River. While some jadeite leaves the mining areas via China, most of the rough material travels south to the city of Mandalay. In conjunction with the IGC conference, one of the editors (RCK)visited the open-air jade market in Mandalay. He found most activity to be centered on 86th Street, between 38th and 40th Streets. On what was described to the editor as a typical business day, easily 5,000 people, buying and selling goods, packed a 500 in stretch of street and a large nearby courtyard (close to the 40th Street inter- Figure 5. Tiny apatite crystals are among the section). At the opposite end, near 38th) in an open area mineral inclusions found in the new emeralds adjacent to the Ah Yoe Ooe pagoda, dealers were selling /rom southern India. Photomicrograph by almost exclusively "utility jade." This material, typically Jayshree Panjikur; magnified 50x. used for carving ornamental objects such as figurines and functional objects like bowls, was sold in such forms as ejected residue of terrestrial rocks that were blasted by small boulders, unpolished slabs, slab fragments (including meteorite impacts. [In fact, two of the strewn fields are the peripheries of pieces from which hololith bracelets had associated with individual craters: Czechia with the Ries already been cut), and lower-quality hololith bracelets (fig- impact crater in southern Germany, and Ivory Coast tek- ure 6). Elsewhere along the street, dealers sold low- to high- tites with the Bos~untwicrater in Ghana.) The Australasian qu'dity "commercial jaden-gem-quality material suitable tektites are the youngest, 720,000 years old; the Ivory Coast for jewelry items and less-valuable gemstones. tektites are 1.02 million years (My) old; the moldavites The fine-quality "imperial jade" was seen in another (tektites from Czechia) are 14.7 My old; and the North jade market, along 34th Street between 85th and 86th American tektites are the oldest, at 34.2 My. Streets. Here, we saw far fewer buyers and sellers, not more Tektites have varietal names based on their shapes as than 200 total. Unlike the larger market, nothing was well as on their provenances. For instance, in the north- western part of the Australasian strewn field, "splash- formu aerodynamic-looking tektites (ovals, dumb-bell Figure 6. At one end of the jade mcuket in shapes, teardrops, buttons) are distinguished from the irreg- Munclulay, Myanmar, a woman sells fragments ular, chunky, and sometimes very large Muong Nong telz- of jucleite slabs and other lower-quality material. tites. Other names include: moldavites [tektites from Photo by Robert C. Kammerbng. Czechia); bediasites and georgiaites [tektites from the U.S.); and indochinites, philippinites (or rizalites), billitonites, javanites, and australites from various parts of the Australasian strewn field. As cut stones, tektites can be difficult to distinguish from manufactured glass. (Moldavites were originally believed to be slag from the Bohemian glass-making indus- try!) Among the characteristic inclusions of this natural glass are: gas-filled bubbles and vesicles, a strongly contort- ed swirling internal structure, small grains or curved tails of isotropic "lechatelierite" (pure silica glass), Fe-Ni spherules, and shocked mineral inclusions. R.I.'s fall between 1.48 and 1.53, and S.G.'s are 2.30-2.52. Tektites vary widely in chemistry, with both R.I. and S.G. increas- ing as the silica content decreases. Tektites have been used since prehistory as ornamen- tal materials and gems, as tools, and as cultural and reli- gious objects (in Europe, Thailand, and West Africa). In some Australian tribes, they were regarded as magical. However, miners in Indonesia have considered them bad omens ill certain alluvial deposits.

Gem News cut sections off the boulder. After each cut, the master would examine the remaining block and mark it with a pencil, indicating where the next cut should be made. The cutting revealed that the boulder was about one-third imperial jadeite, with die rest commercial jadeite. From the better portion, the firm estimated that it would recover 20%-25% of the weight in fashioned goods. If their esti- mate proved accurate, they expected to double their $25,000 investment. The next shop visited produced blanks for jadeite hololith bracelets (the final shaping and polishing was apparently done elsewhere). Jadeite boulders were first cut into slabs on an electric saw. After that, tlie hololith blanks were cut out using a drill-press-like machine with two con- centric circular blades. Another shop produced two types of finished items from the central cores remaining after liololith bracelets were cut from jadeite slabs: small hololiths for infants' bracelets and for stringing together to make jadeite cur- tains, and liololitli rings. For tlie rings, a double-bladed cut- ting tool was again used to cut three double blanks from eacli circular blank. Each double blank was then sawn ill half, producing two ring "preforms" (figure 7). We were told tliat the workers shared 2 kyats [about US$0.02] for eacli preform produced. They produced the ring's final, rounded shape by rotating it on the shaft of a lathe while bringing into contact a fist-sized piece of basalt; for this step, a work- er is paid 1.5 kyats (about US$0.015] for each ring. Another worker polished the ring on the lathe, using the outer sur- face of a piece of baniboo; again, the pay was 1.5 kyats. We Figure 7. In a small lapidary shop Mancialay, in were told that one worker responsible for the last two steps Myanmar, a worker saws a double ring blank in could typically produce 50-60 rings a day. half to produce ring "preforms." Photo by Robert One of the most interesting shops carved jadeite from C. Kammerling. designs created by an artisan-carver or copied from a previ- ously fashioned piece or from an illustration. As an exam- ple of the latter, the editor was shown a photo of a bronze openly displayed. When approached, dealers would take statue of a deity. From this, an acetate template was made small stone papers from pockets or from inside their shirts. with the outlines of the statue. The template was then Almost all the material seen in this market was of very traced on a sawn "face" tliat liad been placed on a sniall good to excellent quality. Although niost were cabochons, jadeite boulder (see, e.g., figure 8). All of the artisans at this one dealer offered gold rings, eacli set with a single imperial shop liad some art training as well as experience as wood- jadeite cabochon. carvers or in carving softer gem materials such as alabaster. Even with this experience, they liad all traveled to China to Jadeite lapidaries in Myanmar. While Myanmar is the learn how to work jade. major commercial source of jadeite, niost is fashioned else- Tools used to work the jadeite include electric grind- where, especially Hong Kong and southern China, as well ing wheels and hand-held drills. All the actual ~uttin~tools as various cities in Thailand. had been made in the shop. The coarsest abrasive for the Still, some Myanmar jadeite is cut in the country grinding wheels was prepared from Carborundum powder itself. While in Mandalay, one of the editors (RCK) visited that had been mixed with a hard waxy material secreted by several small shops in what appeared to be essentially a tree-boring insects. The finer-grit abrasive was made from a cottage industry. One had a single electric-motor-driven mixture of this waxy material and ground, petrified wood. saw, which was being used to cut an approximately 1 kg For tlie final polish, a comniercial dental polishing com- boulder. The piece had been purchased "mawed," that is, pound was used, although the firm was experimenting with a single window ground into its surface. The buyer, a with a diamond powder purchased from China. Using this master with 30 years of jade buying and cutting experience, equipment, in five days an artisan can fashion one 25 cm- had used this window to inspect the interior before pur- tall image of the Buddha or 10 small pendants. The firm chase. Under the watchful eyes of this master, an assistant charges from 1,000 to 5,000 kyats (US$10-$50) per cubic

Gem News GEMS &. GEMOLOGY Winter 1995 last step, polishing, was performed with a wide lathe shaft that was covered with bamboo (figure 9). Unlike the other shops visited, the equipment here was powered by foot pedals. The last stop was at a firm that produced beads. Workers formed them by hand on a grinding wheel. The beads were then drilled with a bow drill, the cutting tool for which was a rod tipped with a small diamond crystal. The other end of the rod was manipulated by the driller. We were told that it takes about five minutes to complete- ly drill a 6-9 mm bead. Workers were paid 2 kyats (US$0.02)per drilled bead.

Freshwater natural pearls from the Lac St. Jean area, Quebec. Francine Payette, a geologist-gemologist from Quebec, Canada, examined the structure and composition of three pearls from the pearl mollusk Margaritifera mui- garitifera, which is found in some Quebec waterways and in a limited area along the Atlantic Coast. (The natural range distribution of this mollusk extends from Labrador to Pennsylvania, along the East Coast drainage of North Figure 8. A partially-carved image of the Buddha America.) (left) awaits final carving and polishing. Black ink Young M margaritifera live as parasites on brown and marks how a sawn jadeite boulder will be carved spotted trout in Quebec rivers. Adults live in the mud and frigllt). Photo by Robert C. Kammerhg. sand on the bottoms of small waterways; they grow shells up to 4 x 6.5 x 15 cm, with brown-to-black exteriors and white (with tints of pink and violet) nacre. There is no commercial pearl fishing in the province, and the cold clj- inch for carving statues. (The exact amount depends on the mate limits harvesting to about four summer months. intricacy of the design.) Ms. Payette, who performed her analyses at the Lava1 We also visited a shop that produces jadeite cabo- University Department of Geology in Quebec, used chons. The cabochons were first rough ground on a vertical cathodolurninescence, X-ray diffraction analysis, scanning grinding wheel, then preformed on a finer-grit wheel. The electron microscopy, and optical microscopy to study thin- sectioned samples of these pearls. Aragonite was the main mineral component, with minor calcite detected. In the Figure 9. One worker polishes a jadeite cabo- interior of the pearl, the aragonite occurs as long, slender chon using a wide lathe shaft covered with bam- crystals radiating from a central point; in the thin outer boo (left), while the other worker preforms a layer, the aragonite occurs as tabular crystals (figure 10). cabocl~onon a grinding wheel. Photo by Robert The contact zone between these two layers is quite sharp; C. l

Unusual pearls. Although today's commercially important pearls predominantly come from a small group of nacreous salt- and freshwater bivalves, niche markets do exist for rare pearls, such as gastropod-derived abalone and conch "pearls," and bivalve-derived wing-shell pearls. However, some pearls are rarer still. Dr. Grahame Brown, of ALL-

Gem News GEMS & GEMOLOGY Winter 1995 GEM Services, Albany Creek, Australia, reported on some rare and unusual pearls that he had seen over the last two decades. He described: A hammer-oyster (Malleus albus) "pearl", which was brownish, pear shaped, and non-nacreous. It had an S.G. of 2.2 and was formed from alternating layers of radi- olucent conchiolin and radiopaque calcite. A brownish nacreous button pearl discovered in a saltwater (edible] New Zealand GreenshellTM mussel [Pernacanaliculus). A bicolored near-hemispherical button pearl, with striking (and characteristic) orient and luster, from the black-banded wing shell, Mangavicula inacmpteia. A porce1;meo~isclam "pearl" from Tridacna gigas of Papua New Guinea origin-a distorted pear-shaped opaque white concretion with an S.G. of 2.80 and no structural characteristics visible with X-radiography. "Coconut pearls" (figure 111, which are manufac- tiired by Indonesian craftsmen from processed thick shell, and which show characteristic striations with "transillu- mination." Highly iridescent natural abalone pearls and cultured abalone half-pearls, with silvery green to brownish red sub- surface colors that continuously shifted as the pearls were moved under indirect overhead illumination. Figure 11. Tlu's 13 mm "coconut pearl" was man- An extremely rare irocl~~zs"pcarl" (from Trochus ufactured in IndonLsia from a thick piece of moth- mtoticus),which displayed a porcelaneous luster but had the er-of-pearl shell. Transillumination ("candling") typical concentric lamellar structure of a natural pearl. reveals the shell structure and cutting marks. Dr. Brown also described an early cultured pearl neck- Photo courtesy of Grcihame Brown. lace of Australian origin. Evidence suggested that the pearls were cultured in the Australian P. maxima during or before William Saville-Kent. Mr. Saville-Kent operated a pearl-cul- the first decade of the 20th century, by the Englishman tiiring farm on Albany Island, just to the east of Australia's Cape York, between 1906 and 1908. Dr. Brown proposed that Mr. Nishikawa and Mr. Mise, generally accepted as the Figure 10. This SEM photomicrograph clearly illus- first to culture round bead-nucleated pearls successfully, may trates the long aragonite crystals radiating from the have learned the technique by observing Mr. Saville-Kent's core, and the outer layer of tabular aragonite crystals, experiments on or around Thursday Island. in a naturellpearl from the Lac St. Jean area, Quebec. Photomicrograph courtesy of the Departn~entof Rubies from the Bmhgton volcanic Beld, East Australia. Dr. Geology, Lava1 University, Quebec, Canada. F. L. Sutherland, of the Australian Museum in Sydney, described faceting-quality rubies found in alluvial deposits shed from the Tertiary Barrington basalt shield volcano in eastern Australia. The rubies accompany sapphire, zircon, spinel, and other heavy detrital minerals (figure 12).Crystals show corrosion from transport in a hot fluid; the main min- eral inclusions in these crystals are pleonaste (ferroan spinel) and clmrnian pleonaste. The ruby grades into pink sapphire with a decrease in chromium and iron contents. The parent rock-found as small mineral aggregates accompanying the gem corundum-contains ruby, sap- phire, sapphirine, and spinel, with a reaction-rim of pleonaste spinel (from transportation in a hot melt) some- times visible. Sapphires that crystallized with the ruby are near-colorless, or are found in pastel shades of yellow, blue, green, or pink. The sapphirine is usually blue to green, with a composition of about 7MgO-9Al@3*3Si02 with some iron substitution. The spinel is opaque pleonaste and chro-

Gem News GEMS & GEMOLOGY Winter 1995 ruby fields in Thailand (Rubywell mine]. This raises the potential of sapphirine as an indicator for ruby sources.

Ruby market in Taunggyi. For many of the rubies mined in Mong Hsu, the first stop after the mines is the ruby market in Taunggyi (Myanmar). In early November 1995, in con- junction with the IGC conference, one of the editors (RCK) visited this important gem-trading center. Located near the outskirts of the city, the marlzet is in an enclosed con~poundreminiscent of (but larger than) that at Luc Yen in northern Vietnam. For the most part, dealers sit at small tables (figure 13))for which they pay 200 kyats (about US$2) a day. Even though business was described as "light" on the day we visited (which followed a holiday), we conservatively estimated that some 2,000 people were in the compound at the height of activity. We were told that 10,000 people typically crowd the market on a more normal work day, but that this is half the number seen the Figure 12. This 3 n~m-longruby grain with attached previous year. cluotnian spinel crystal is from the BarringLon vol- This drop in activity apparently does not relate to canic field in eastern Australia. Photo by Gayle problems in Mong Hsu: Several people confirmed that Webb;0 Australian Museum, Sidney. there has been no decrease in mining activity, and material continues to move freely to Taunggyi. Rather, the marlzet reportedly has been affected by a drop in the prices paid for mian pleonaste. Sapphirine-spinel thermometry suggests Mong Hsu material, because of increased difficulties in get- that these aggregates crystallized at about 780°-940° ting it out of the country. In the past, material freely This suite of associated minerals contrasts with the crossed from Tachileik, Myanmar, into Mae Sai, in the far more common sapphire suites in eastern Australia, which north of Thailand (see "Update on Monghsu ruby," Winter typically contain blue-green growth-zoned sapphire crys- 1993 Gem News, pp. 286-287). However, about six months tals. Such sapphires contain inclusions of rutile (silk)and before the editor's visit, the Myanmar government closed iron-rich spinel, as compared to the pleonaste inclusions in this land link. Material now travels a more circuitous, and the Barrington corundum aggregates. The association with perhaps less-secure, route from Myanmar into haila and. sapphirine seen at Bairington also appears in some alluvial We were told that much of the Mong Hsu material was being diverted to the Thai border towns of Mae Hong Song and Mae Sot. Figure 13. Two young women sort rough rubies Although rubies dominated the Taunggyi market, we from Mong Hsu at the gem n~arlearrings and large pendants set with many small, faceted rubies (figure 14).When asked the source of their stones, most said that it was Mong Hsu.

Sapphire mining in Laos. Southeast Asia is famous for its corundum deposits: Myanmar has Mogolz and Mong Hsu; Thailand has Kanchanaburi and Chanthaburi-Trat; and Cambodia has Pailin. The newest addition to this group of corundum producers is Laos. In a brief report in the December 1994 ICA Gazette, a Laotian locality called

Gem News GEMS & GEMOLOGY Winter 1995 When the shaft was too deep, the miners hauled the buck- ets to the surface using a bamboo pole fitted with a hook on one end. When enough material had been extracted, it was sift- ed through a large-mesh basket to remove any large rocks and then loaded into a plastic grain sack, which die miner then carried to a small stream some 200-300 m away. Here, the soils were shoveled into wide, shallow woven wicker baskets, like those used in many parts of tlie world for washing gem-bearing material. Because the stream was very shallow, the miners used shovels to dig depressions in the stream bed deep enough to permit washing. Once tlie soil had been washed away, the miners would examine the gravels and remove any sapphires found, often while still sitting in the stream (figure 16). The editor had an opportunity to briefly examine some of the sapphires, both at the washing site and at a local dealer's honie. These sapphires ranged from light to dark blue (figure 17),with many noticeably color zoned. The overd impression was that some fine-quality material was coming out of tlie area. Although most of tlie rough was small (one carat or less), we saw some stones of several carats.

The sapphire deposit in southern Madagascar. Sapphires Figure 14. This woman, like many of those buying from new mining operations near Andranondamtso, and selling gems in the Ta~inggyimarlcei, wears Madagascar, were described by Contributing Editor Dr. ruby-set earrings. Photo by Robert C. Kamn~erling. Henry Hanni, on the basis of work done with colleagues Michael Krzemniclu and Drs. Lore Kiefert, Karl Schmetzer, "Huai Sai" was said to produce good-color blue sapphire. and Heinz-Jurgen Bernhardt. Andranondamtso is a small More recently, in the August-September 1995 issue of village north of Tolanaro (FortDauphin). fewelSiazn, David Squires described a brief visit to a mech- anized mining operation near die Laotian border town of Bail Houay Xai. Fig-we 15. At a sapphire-~nitimglocality near Ban Also in conjunction with die 1GC conference, one of Houay Xai, Laos, a miner passes a bucket of soil the editors (RCK)visited a mining area not far from Ban and gravel to a co-worker. Photo by Robert C. Houay Xcu. Starting from the city of Cliiang Rai in north- IZammerllng. ern Thailand, the editor and a few colleagues drove approxi- mately one-and-a-half hours on a paved two-lane road to reach Cliiang Khong, a Thai border town on the Melzong River, roughly 70 air ndes (112 lam) northeast of Chiang Rai. After arranging for a one-day entry permit to enter Laos, the group crossed the river by long, narrow power boat to Ban Houay Xai, where we rented two 41samlors" (motorcycle taxis) for the drive to the mines. The first site visited was Ban Tong Saeng Chan, which translates as "field with moonhght," about 15 lun south- east of Ban Houay Xai. The mining area was a large field that had been pierced by circular shafts about 1.5 m in diameter and 2-3 m (6-9 feet) deep. Miners reached the bot- tom of the shafts by climbing down bamboo poles. They used short-handled shovels to dig the shafts (and some- times short tunnels-no more than a meter or so~intothe gem-bearing layers). Miners used either the shovels or small metal bowls to extract the gem-bearing lateritic soil we saw no distinct gravel layer in any of the pits). The extracted material was then placed in a bucket and, in shal- low shafts, handed to a co-worker at the surface [figure 15).

Gem News GEMS & GEMOLOGY Winter 1995 Mineral species identified in the (very calcite-rich) associated parent rock include: calcite, feldspars, quartz, diopside, mica, anatme, spinel, apatite, wollastonite, and a mixture of clay minerals. Inclusions found in the sapphires are: apatite, calcite, spinel, diaspore, C02, and nitile. These were identified by Raman spectroscopy and SEM-EDS. Rutile needles were not present or were very small. Turbid areas in the crystals may be composed of fine, s~ibmicro- scopic TiOi precipitcites. Because many crystals have sec- tored color zoning and/or turbid areas, sapphires from this locality will probably need heat treatment to be mar- ketable.

Scapolites from new discoveries in Sri Lanka. The geinolog- ical properties of scapolites from Sri Lanka were discussed by Pieter C. Zwaan, of Leiden, the Netherlands, and E. Gamini Zoysa, of Mount Lavinia, Sri Lanka. These yellow to near-colorless stones came from eluvicil and alluvial deposits near Pohorabawa, a small village in the Eheliyagoda area, and in the Embilipitiya area. The Eheliyagoda specimens had mean refractive indices of 1.542 (extraorbmy ray) and 1.560 (ordinary ray), birefrin- gence of 0.018, specific gravity of 2.632, and composition of Marialite67,5Meionite32,5.There are two groups of Embdipitiya scapolites: one with gem properties similar to those from the Eldayagoda area, and the other with refrac- Figure 16. Soil and gravels, recovered from pits tive indices of 1.550 (extraordinary ray) and 1.578 (ordinary like that shown in figure 15, are washed for sap- ray), a birefringence of 0.028, a specific gravity of 2.693, and a pl~iresin a local stream. Photo by Robert C. con~positionof Marialite4nsMeio~~g,5.This second group Ka~nrnerling. of scapolites also may contain needle-like inclusions of pyrrhotite. Scapolites can be distinguished from other yellow Sri Lankan gemstones with similar properties (such as citrinc The Tranomano Precambrian crystalline schists are and various feldspars) by their strong orange-yellow to embedded between the Anosyenne chain and the Androy volcanics in southern Madagascar. The Tranoinano units form the central part of a peneplain; these crystalline schists were subjected to strong (granulite facies) metamor- Figwe 17. This handful of sapphire rough, seen at. a phism, and consist of pyroxenites, garnet gneisses, and mining site near Ban Houay Xai, appears to be typi- pyroxene gneisses. These rocks were folded and a granitic cd of the sapphi~esbeing produced in the area. Photo mass intruded, from which pegmatite dikes emanated fur- by Robert C. Kamn~erhg. ther into the pyroxenites. Sapphires formed locally in the reaction zones between the pegmatite dikes and the pyrox- enite; these deposits take the form of nests and pockets. The sapphire crystals are usually small (5-15 mm across) and are light-to-dark blue in color (figure 18).Crystal shapes observed vary from columnar to pyramidal and distorted tabular shapes; crystal faces identified so far include c, a, r, n, w, z, and a rare scalenohedral form. These faces not only define the surface morpl~ologyof the crystals, but they also are frequently encountered within the crystals, where they form growth and color bands. Electron microprobe analyses revealed significant variations in the concentrations of chromophore elements Fe (0.15-0.25 wt.% Fe as Fe203) and Ti (0.05-0.15 wt.% Ti as TiO2).The absorption spec- trum is sindar to that of Sri Lankan and Burmese sapphires, with a weak-to-moderateFe3+ absorption at 450 run.

Gem News GEMS & GEMOLOGY Winter 1995 "canary" yellow fluorescence to long-wave UV radiation and their much stronger birefringence. With regard to gemological properties, Eheliyagodii scapolites have much in common with those from Tanzania, whereas most En~bilipitiyascapolites are very similar to scapolites from Madagascar. Among the scapo- lites from other localities that were available for identifica- tion was a 2.06 ct violet stone from Palustan, which had the lowest numerical values for physical properties and the low- est meionite content (composition maria lit^,^ Mei~nite~,~) ever observed in the Netherlands Gemmological Laboratory.

T'inz.anites and other zoisites from Merelani, Tanzania. Why do so many colors of zoisite come from such a small area in Tanzania? Why does some zoisite exhibit a color change after heat treatment, wlde some does not? To answer these questions, Contributing Editor Henry Hanni [aided by Daniel Traber and Dr. N. Barot], analyzed 42 zoisite crystals and chips both chemically and spectroscopically. Chemical investigations were carried out by micro- probe, with special attention given to the chromophores Fe, gle crystals. Dr. Schmetzer identified as external crystal Ti, Cr, and V. Quantitative results showed low aluminum faces (dominant faces underlined here for emphasis) pina- contents [compared to the ideal zoisite formula). This sug- coids a [lOOL b (OlO], and c (001);rhoinbic prisms s (120), gests substitution of the chromophores for Al, either as a k (0211, x [IOIL and m (110);and one rl~ombicdipyrainid simple substitution or coupled with some other substitu- o (1111. X-ray fl~iorescencespectroscopy revealed minor-to- tion. Brown and blue samples typically had a V2O3/Cr2O3 trace amounts of Cr, Fe, V (in some samples), Ce, Bi, and ratio greater than two; this ratio was less than two for green Mo. Cr, V, and Fe are chromophores. Bi and Mo were samples. Light blue crystals with elevated Ti02 contents already known to be components of the flux material used showed only a weak response to heat treatment, despite in Russia for the growth of synthetic alexandrites, but the their vanadium content. Manganese and iron were found in presence of germanium, sometimes greater than 1 wt.% very low concentrations only; hence, the authors did not GeOT,was surprising. consider these elements to be relevant with regard to the The crystals showed growth zoning parallel to the four colors of the Merelani zoisites. A green zoisite from dominant a, x, lz, and o faces (figure 191, which was also Pakistan and a pink zoisite (purchased in India) were tested seen as zoning of Cr, Fe, Ce, and V (again, in some samples) for comparison purposes, and were found to have signifi- with the electron microprobe. About 10% of the samples cant iron contents. revealed an intense red (in incandescent Ught) core, with a Violet zoisites owe their color to V3+. The addition of a lighter red rim, and a rounded, still more intense red bound- little Cr^ results in a purer blue. The transition from ary between the two. Chromium content ranged up to 4 brown to blue is caused by destruction of the 450 nm wt.% Cr203 in the boundary area, which indicates a two- absorption band on heat treatment. (Both the brown stage growth process for some of the synthetic alexandrites. pleochroic color and the 450 run absorption band are polar- ized parallel to the c-axis.) Samples with elevated Ti con- GGG as a corundum fake. Over the past few years, reports tents (which are usually light blue] showed weak reactions have appeared here and elsewhere about the danger of inad- to heat and kept the 450 nm feature to a certain extent. vertently purchasing synthetic rubies that have been fash- The authors speculate that the color transition mechanism ioned to resemble waterworn natural rubies from Vietnam (with heat treatment) is: Ti& + V4+ converting to Ti^ + V1"^ (see, for example, Winter 1991 Gem News, p. 260). We as titanium is oxidized with heating; they hope that further have also heard of an imitation Mong Hsu ruby that is pro- investigation will confirm this hypothesis. Finally, they duced by inserting a blue, wax-like substance into a cavity noted that infrared spectroscopy revealed no features that in synthetic ruby; the wax superficially resembles the blue would be diagnostic for heat treatment in zoisite. central zone typical of material from that locality. While in Taungyi, Editor R. C. Kan~merlinglearned SYNTHETICS AND SIMULANTS - of another deception being used on local jewelers: Large Russian flux-grown synthetic alexandrites. One of the con- pieces of purple CCG are fashioned to resemble corundum tributing editors, Dr. Karl Schmetzer, examined about 200 crystals and misrepresented as material from a "new" crystals of flux-grown synthetic alexandrite obtained from deposit. One such imitation, shown by U. Tin Hlaing (who Novosibirsk and Bangkok. About 90% of the crystals had identified the specimen as CGC), had a rough-ground showed cyclic twinning; the balance were untwinned sin- surface with fairly convincing parallel striations on the

Gem News GEMS & GEMOLOGY Winter 1995 Nuclear ~nicroscopyof rubies. Mr. Tay Thye Sunl of the Far East Gemological Laboratory! Singapore! described the use of a nuclear nlicl-oscope to determine trace-elei~~entcon- tents in nibies. In this research' camed o~itin collaboration with the National University of Singapore Nuclear ~WcroscopyGro~ip! a foc~~sedbeam of hgl-energy protons is raster-scanned across the sample's s~~rface;X-rays (Particle lndiiced X-ray Emissionl or 1'IXE) and backscat- tered protons (Baclzscattering Spectroinet~y,or BS) are col- lected from regions as small as 1 micron. Depths of around 30 microns are probed. The method allows the determina- tion of trace-element concentrations at the 1 ppm level from homogeneous regions near the stone's s~u-face'where no inclusions or surface contaninations are present. In addtion to the six rough samples from Mong Hsu and fo~ucut stones from Thailand that had been st~~cliedin detail) Dr. Tay presented preliminary results for 105 rubies fro111 vario~~sMyanmar localities. The Thai stones had higher Fe contents than the Mong Hsu n~bies!but the Mong HSLIstones had more V ancl Ti, The dark ~MongHSL~ core regions were high in Cr and Ti.

R:i~iianspectrolneters. Interest in Ran~anspectroscopy as a gemological technique continues to grow because of its ~isef~~lnessas a nondestn~ctivetechicl~ie to identdy inc1~1- sions in genlstones. Dr. Prof. Bernard Lasnier! of the Gen~n~ologyLaboratory at the University from Nantes! France! reported tl~tthe technology of gemological Raman Figure 19. This R~ission~~LLX-grown syntl16~ic (11exan- spectrometers contin~iesto improve; Han A, Talay of the drite shows a characteristic growth pottern consist- University of Nantes has developed a new unit that is ing o\ two a (100) pinocoids (left ond right) ond two portable (it weighs 15 kg) and can also be used for colori- o (1 11)rhombic dipyramids (top). l'hotomicrograph metric ineasureinents. (ilnn~ersion,incondmcent light) co~rtesyoj Karl Schmetzer; magnified 40x. Figure 20. This rough "crystd'' o/pwple GGG was niisrepresented to a jeweler in Ta~mggyi,Myanmar, os o corzrndzzm gem from o new locoliiy. Pho~oby crystal "faces1' (figure 20). Because of the rough surfaces! it Robert C. Kalnmerhg. was difficult to eramine the interior of the piece, even with strong transmitted light. However! its deep purple color was very evident, Unwary jewelers! seeing this transmitted purple color, n%ht mistake it for a mixing of colors from the red periphery and blue core of a Mong Hsu-like crystal.

INSTRUMENTATION The lapidary as a gemological resource. Michael Grayl of Graystone Enterprises! Missoulal Montana) pointed out that lapidaries-the people who faslion gem ro~ighinto cut stones-can be an invaluable source of gemological infor- mation! especially with regard to new materials, and locali- ty and treatment information. For instcancel the fact that benitoite was too soft to be sapphire provided the first cl~ie that it was a new mineral. In Mr. Gray's experience) heat- treated corundums do not responil to cutting and polishing in the same way that int treated stones do! and bicolored tourmalines from different localities behave differently dur- ing faceting,

GEMS & GEMOLOGY Winter 1995 Dr. Jamie Nelson) of London) Eilglandl provided a vev lucid description of how the Ra~naneffect worlzsl and reported that he is developing a catalog of Raman spectra of gemstones and their inclusions, whch currently contains 150 entries. [For LIII existing catalog of 80 Ramail spectra of gems and their ii~clusio~~slsee the 1992 special Ran~an spectroscopy iss~~eof Revue de Geznmolog~e[abstracted by E. Fritsch ill the Fall 1993 Gems ed Geznologyl p. 2241. A inore extensive catalog-wit11 more than 600 ~nhleralogical standards-is currently in press in Nantes.) Gany du Toit) of the Asian Lnstit~~teof Gemological Scieilces in Bangl

Brewster angle refracton~eter.Dr. Roger Harding, of the Gei~~~nologicalAssociation and Gein Testing Laboratoiy of Great Britajn! described an instrunlent that worlzs by inea- suring the angle at whicl~the light reflecting off the s~dace Figzue 21. Gems & Genlology Editor Alice Keller ~tccepts of a geinstone is inost highly polarized [heBrewster angle). the trop11y for best scientific/ed~1cotiono1feature mticle A laser serves as the high-intensity monochron~aticlight from ASAE Prcsidei~tR. Wfiflrn Taylor. source; however! as the lasers en~ployedto date enlit light in the red end of the spectiunl (632.8 or 670 nil^]^ and not at the 589 n111 sodium D linel the ineasurenlents 111ust be The necldace wit11 cloisoi~i~ebeads, aild all the otller converted (that is) the dispersion must be lznown] in order pieces! contained cloisonn6 inset with lapis laz~11i~car- to coinpare results wit11 conventional refractonleters. Thus! nelianl agate! and t~lrq~~oise.LI one piece) aillazoiite WEIS a table of Brewster angles (at 670 nm) is IIIOI-e convenie~lt used to imitate turquoise in an inconspicuous place. All for recording and conlparing data. Wit11 this instniment1 the pieces showed signs of wear and weatllcrii~g~suc11 as the Brewster angles of dianlond and CZ can be distin- stones missing from the enainel worlc and the alteration of guished) and no optical co~~plingfl~lid (SLIC~ as K,I, liquid) is soille lapis lazuli causecl by pyrite decomposition. They needed. also showed that cul~~~re'sappreciation of turquoise and lapis laz~~li!and the infl~~enceof neighl>oring civilizations. MISCELLANEOUS Gems in ancient jewelry. Jewelry from a 4th century B.C. ANNOUNCEMENTS sepulcher was the topic of a talk give11 by Jean-Paul Poirot) Gems ed Gemology wins again. For the fo~irtllconsecutive of the Service Public ~LIControle des Diamants, Perles year, Gems & Gemologj7 won an award in the prestigious Fines et Pie~~esPr6cieuses) Paris. The sepulcher was of the American Society of Association Executives (ASAE) Gold Acllemenid period in SLIS~[modem J.ran], Circle competition, For 1995, the jounlal rece~veda first- The gems i11 three beaded neclzlacesl two buttonsl two place trophy in the category "Feat~11-eWriting, ear pendantsl one torque) and two bracelets were identified. Scientific/Ed~~cational"for the article "An Update on Filled Drilled beads from one single- and one four-straild neclzlace Dian~onds:Identification and Durability," by R. C. included: quartz (roclc crystal) amethystl smolcy q~lartz); Icarnelian! sardoi~yx~ T. M. Moses) E. Fritsch, and J. E. Shgley [wllicll appeared in onyxl brown banded agate! red ai~dyellow jasper) and other the Fall 1994 issue 2nd was thc recipient of Ge111s ed chalcedony) and siliceous roclcs; hematite and ferruginous Gemology's own "Most Valuable Article" award). Geins roclq feldspar porphyries with b1;lclc body colors; and liil~e- Gem01ogj~also placed second ovesall in the llJo~~mals'lcat- stone! mother-of-pearl! amazonitel turquoisel nlalachite, egory. Editor Alice Iceller traveled to Cl~icagoin early serpentine) lapis lazuli, gold beads, and "artificial prod~icts" Decenlber to receive the tsoplly on behalf of thc jo~~rild [sintered glassy frits wit11 bluisll white body colors). [figure21).

Gel11 News GEMS 13GEMOLOGY PHOTO MASTERS FOR mid-1600sl the use of table-cut dia- DIAMOND GRADING monds and the introduction of rose- cut diai~~ondsllelped move jewelry By Gary A. Roskin, 94 pp., illz~s., design away from elaborate precious- publ. by Gen~worldIiiternationol, metal and enainel w0r1<~reducing North brook, IL, 1994. US$75,00* their role to that of decorative motif. By the title alone, I anticipated Photo A scant 40 years later! Parisians Masters /or Dian~ondGruding to be a deinanded more facets on the sides of practical combination of E. Gtibelin table-cut diainoncls-the first recorded and J. I. Koiv~ila'sPho~outlas o/ attempt at the brihant CLI~.Silpporting Inclz~sionsin Gemstones and GIA this historical footnote, Jan Walgravels GEM Instri~ment'sh4icroVision 2000, article on "Diainond C~itsin the 17th After reading I'hoto Mastersl I realized Century" definitively states that "The that it is not intended to be a "mas- incl~isions~butl beca~iseeach is brilliant [cut diainond] exists already ter" for grading in the sanle sense that show11 at a ddferent i~~agrufication~it before 1700 b~~tonlv soine decades "master color1' coin~arisondiamonds is impossible to coinpare thein. later completely s~ipersedesthe table are ~lsedfor color grading, The value Tlle last chapter, on Laboratory diamond." 7;in Walgrave also provides of this book is as a reference guide for Comparisonsl seems to have one aim: articles on "Tendencies in 17th- the trade, mainlv for retailers and to show SI3 clarity grades where they Century Jewellery1I and a description nisty diainond graders. I used it with a had not been shown before. Even sol of the miniature case of Icing LOLI~S custonler in nly store to clarify the the disc~issionis incomplete and XIV of France! given by that monarch difference between a WS2 feather and leaves the iss~ieof differences between to a D~itchenvoy in 1683, a VSl feather. It provided the example laboratories inr resolved 1e.g.) the GIA Diana Scarisbrick! noted British we needed without my actually look- Geln Trade Laboratory does not use jewelry historian! writes an absorbing ing through dozens of loose diamoi~ds. th~sgrade). hl this reviewer's opinioi~~ 13-page article) "17th-Cent~iryDia- This glossy hardcover book has it is inappropriate as a concl~iding mond Jewelery and the Ori~ainental more than 200 color photomicro- chapter to a boolz that puqorts to be Print." She relies on the ornanlental prints that were p~iblishedfor jewelers graphs of diamonds representing all striving for consistency ill diainond and their clients to trace the history of clarity grades and other grading char- grading. jewelry from the end of the 16th cen- acteristics. It is well organized! with a Neverthelessl this boolz acheves tury to the reign of Louis XIV at concise table of contents! enjoyable its stated p~irposeof helping to reduce ii~trod~iction~and a good history of the inconsistencies in grahg! and it is a Versafiles. , 111 the act~ialcatalog portion of evolution of diamond grading. For the val~iabletool for the appraiser! wllole- the boolzl a rich narrative accompa- most pilrtl the caption to each pho- saler, and retailer, As a retailer and tomicrograph gives the diainondls former diainond grader, I wo~ildgive nies each of the crisply ill~istrated107 jewelry items. Many of the ill~istra- carat weight! clarity grade! level of Photo Masters for Diamond Grciding tions show details of the counter magmfic~itionl'and the grading labora- an S12. . . Salable b~ith~coinplete~ too. toiy, if any. However! not all captions engraving or counter enameling give all of this inforn~ation~and this STEVEN L. GINSBERG[ G.G. prevalent at that time. LI a number of boolc sho~ildcontinue to be ~ipdated. Ginsberg ]e welers instancesl a line drawing of the The m21in grading issue Roskin Cedar Rapids, IOW~I faceted dian~ondaccoinpanies the deals with is clarity, Altho~igl~this photo and text. boolc wU not thnist you into the ckcle A SPARKLUNG AGE, 17~~- Altho~ighthis book laclcs a table of the professional diamond graderl as CENTURY DIAMOND of contents! g~ossarylor index, it is rel- the title and preface might imply! it JEWELLERY atively easy to follow along chrono- does offer a second opinion to help the 10gic;dly. The reader can vis~idytrack reader strive for "consistency in an 223 pp., illus., pzlbl. by the trends in jewelry design and diamond evolving grading system." Neverthe- Diamantmuse~~m,Antwerp, c~itsas they emerge and are refined less, inore pages should have been Belgizin~,1993, US$65.00* d~lringths fascinating era. For those devoted to the claritv iss~le.I also felt This bilingual (Flemisl~/English]cata- interested in specific items or types of that the chapteix on Reflectors, Fancy log of an exhibition held at the Province jewelry, thought browsing wo~ildbe a Shapes! Fancy Colorsl Large Diamonds, Diainond M~ise~imin Antwerp June problem. and Rec~ittmgwere far too short. 11-October 3! 1993/ capably deinon- GAIL BRETT LEVINE Anothe~concern is vis~ialpercep- strates the splei~dorof diainond jewel- A ~ictionMl~rket R~source tion as it relates to the use of pho- ry in the 17th century-aptly called "A Rego Park, New York tomicrographs, A common magmfica- SpaiMir~gAge." This soft-cover boolz tion level IiOxI for all diainonds ill~is- offers rich insghts into both the devel- trated wohld have provided a much opment of cliainond c~itsand cl~anghg 'This bmk is avajlable for purchase through the GIA Bookstore, 1660 Stewart Street, more re& tic comparison withany tastes in jewelry d~ringthis era. Santa Monica, CA 90404. Telephone (800) one clarity grade. AS presentedl one Fo~irarticles provide baclzgroui~d 421 -7250, exf. 282; outside the U.S. (310) can Ioolz at a dozen different VS2 infori~~ationfor the exhibit. In the 829-2997, exi. 282. Fa: (37 0) 449-7 7 67.

Book Reviews Winter 1995 288 GEMOLOGICAL ABSTRACTS

C. W. FRYER,EDITOR

REVIEW BOARD Juli Cook-Golden Robert C. Kammerlin~ Gary A,Roskin Charles E. Asllbau~hIll Royal Oak, Michigan GIA Gem Trade Lab, Sanla Monica European Gemological Laboraloy Los Angeles, Calilornia lsolope Producls Laboralories Michael Gray A. A. Levinson Burbank, Calilornia Missoula, Monlana Universily 01 Calgary Jana E. Miyahira Andrew Christie Patricia A. S. Gray Calgarj Alberla, Canada GIA, Sanla Mon~ca GIA, Sanla Monica Missoula, Monlana Loretta B. Loeb James E. Shigley Jo Ellen Cole Professor R. A. Howie Visalia, Calilornia GIA, Sanla Monica GIA, Sanla Monica Royal Holloway Carol M. Stockton Maha DeMaggio Universily 01 London Elise B. Misiorowski Alexandria, Vir~inia GIA, Sanla Monica Uniled Kingdom GIA, Sanla Monica Rolf Tatje Emmanuel Fritsch Mary L. Johnson Himiko Naka Duisburg Universily Universily of Nanles, France GIA Gem liade Lab, Sanla Monica Pacific Palisades, California Duisburg, Germany

COLORED STONES ANLl ters to S371000oysters aiu~ually[16100~100,000 p3.~i com- ORGANIC MATERIALS pany). Alinost all are harvested off SO mle Beach, west of Building a new image for Australian pearls. R. Sl~or~ Brooine. However, Australia will allow each conlpany to [ewelers Circ1i1ar-lZeystone, Vol, 166/ No. lol add 20,000 hatchery-grown oysters to its operating stoclc. October 1995, pp. 72-74, 76. Hatcl~eiypearls are described as "more ~lniformand much less exciting." JEc Australia's 16 pearl farmers have decided to aggsessively n~:ulinnovations by tions are no longer acceptable and sho~ildbe discarded. the AustraLian farmers have lowered ~noll~~sl

Gelnological Abstracts GEMS & GEMOLOGY Winter 1995 Their decisions anhave implications for gemologyl espe- pearls. In this article, the authors show that "fI;it pe;u1s1'- cially on the criteria for natural as compared to "n~cin- iridescent regions of oriented colu~nnsof flat aragonite inade" materials. III this article, Dr. Nicliell vice-chair~nan plates-ca~~11e grown on disks of glass, nica, and ~nolyb- of the CNMMN, explains the current definition used to denite (1MoS2Jinserted between the mantle and shell of red determine whether a substance is a nineral. :ibalones, Haliotis rufacez~s.The development of pearly "In general terms! a mineral is an clement or chemical layers appears governed by processes in the abalone mantle compo~lndthat is ~~ormallycrystalline and that has been cells that are triggered by the presence of inorganic materi- formed as a result of geologiciil processes." By this defin- id between the mantle and the shell. tion1 an~orphoussubst~mces (such as opal] usually are not Abalones were chosen for these experiments lxcause considered n~inerals~although there are a few exceptions they grow nacreous i~~aterialfaster (about 26 tin~es)than (georgeite! c:ilciourmoite], Metainict materials (that is, bivalves, and they lacli the coinplicated bivalve "pearl sac." materials made amorphous by large amounts of radiation Eighteeil-idlii~~eter-diai~~eterdislcs of glass! inic;il zu~d dainage) may be accepted as ininerals if there is evidence inolybdenite were inserted between the mcmtle and the that the material was crystalline before radiation damage. shell in living red abalonesl and then reinoved 14 days later; Virt~iallyall liquids are not ininerals (the exception is iner- nacreous layers grew on all three types of clisks. To better CL~].However! when solidified (SLICII as ice)! they may be ~inderstandthe depositional processl the authors repeated minerals, even if they are not stable at rooin temperature or the experiments! withdrawing the dislzs at shorter intervals, ainbient presstire. Extraterrestrial substances (such as the They found the following sequence: (1] The first material to lunar n~ineraltranquillityite] can be minerals. Geologic be deposited was calcite) whch grew in 100 LI intergrown processes are not limited to those on Earth! crystalline bloclzs (day five); (21 the first aragonite n~icleated For gen~ologists,the debatable materials are biogenic in discrete sites on this calcite surface after scven days; and (formed by living creat~ires]~a~thropogeiuc (forined by (31 highly ordered coluinnar aggregates grew from these humans]l or anthropogeiuc with later geologic modifia- nuclei

290 Gemo~ogicalAbstracts GEMS & GEMOLOGY Winter 1995 Other gemstones. C. R, Cavey' Metals cd Mizierals Ann~lal Rare natural pink clinozoisite (in Japanese). Y. KitawalNorway. There was little evi- Canada has joined then1 for the testing phase of a new prop- dence of mining in the region aro~~ndthe Tajilustan- erty' Kyle No, 3. As of July 31' 1995,96 microdiamonds (less Afghanistan border. than 0.5 min in maxiiniim dimension) and five macrodia- Sri Lanlci produced "large q~imtities''of s;ippl~iresand monds had been recovered from 454 l~gof kimberlite drill is adding more gem-cutting kind polishing centers; local core, Most garnets from the discovev hole plot "well with- interest hheat treatment also expanded) in response to a in" the GI0 range favorable for diamonds, and chro~nite growing rel~ictanceto send stones to Thailand for process- compositions appciir fi~vorablc~too. ing. Thailand contin~iedto prod~icemedium- and low-q~ial- Ashton is also evaliiating di:iinondifero~isproperties i11 ity (with small amoiints of good-qiiality) sapphires. In addi- the Northwest Territories) as well as near Lake S~iperiorin tion, large amounts of Sri Lanlcan) A~istralian!Nigerian, and the U~tedStates. Chu~esestones are imported into Thailand for heat treat- ment. Nigeria contin~iedto mine dark blue sapphesl and Botswana backs renewals with the CSO. A. Katz! Mozd nlany colors of corund~iincame from the Umba River U'Brachal No. 67) May 1995, pp. 96100. Valley in Tanzania. Sapphe mining co~~tinuedin Mo~ltana~ Botswana has become Africa's econo~nicsLiccess story a few stones were found in Madagasc~~and a dark beca~iseof its diamond and other mineral resources. bl~ie/brown sapphire of inore than 11000 carats was Mr. Archibald Mopel Botswana's Minister of Mineral runlored to have been fo~indin Yeinen. Resources and Water Affairs, believes that his country Emerald production increased in Colombia, with some is a wealthyl stable democracy becd~iseit has muntkiined gems wei- more than 50 ct; however! virtually all the control over its n~.ineral-richland. At a recent di;imond con- stones were subjected to "resin in-filh~g.''Brazil's emerald ference in Perth' Austraba) Mr. Mogwe gave De Beers hgh o~iputremained stable. Prodiiction from Africa-from marks for ~1neartl-u~the resources by which "Botswana Sandawana and other sites in Zimbabwe, Zambia' lives or dies." Since the mid-1960s) Botswana and the CSO Mozambiq~ie~Nigeria) and South Africa-was erratic in have been equal partners in that co~intry'sdiamond mining 1994. There was a11 unconfumed report of a "fine emerald1' and ~narl

Ge~nologicalAbstracts GEMS &k GEIMOLOGY Winter 1995 29 1 monds from the western region of the Central Ahcan carats (Mct)of gem and near-gem diamonds, about the same Republic were examined by scaring electron microscope as 1993, :iccording to sLqtistics released by the U.S. Bureau to determine their geologic history, The marks observed of files. The only leading producer with any sigmficant were related to two distinct periods of transport: magmatic change WAS Zaire, where o~itputfell 5.2% (to9 Mct)because and hyctra~ilic. of contin~~inggovernment instability. Australia, the largest The dia~nondsunderwent ~igmfic~mtmagllatic corro- prod~icerof gem diamonds by weightJ yielded 19 Mct; sion during their ascent from the upper mantle, Evidence Botswana, the largest producer by valuel totaled 12 Mct. for this incl~idedthe fact that there were more rhombdo- Russia mined 8 MctJ whch was equal to its 1993 pro- decaheciral than octahedral formsl the frequent occurrence duction but down 11 % from 199G;i drop probably c:i~ised on the crystal faces of pyra~nidaldepressions with triangu- by the ~nkiturityof the major R~issianmines, Russia is mov- lar (11 1) or square (100)basesJ and the presence of V-shaped ing closer to production, but stdl in the testing phase, at six (I 11 ] or stepped figures on the faces around the ternary axes, major lun~berlitepipes at .ArchangelsI<, Some impact marks probably occ~irreddui-ing the explosive So~ltl~Africa produced 4.3 Mct in 1994. Na~nibia'sout- episode of lhberlite extrusion. put was 1.1 1Mct; mine ownership there WAS partially Other impact n1ar1Western Australia). Fifty mil- Ovcr the next 14 n~onths,these deposits produced 387J000 lion carats of ind~~strialdiamonds were n~eclin 1994, with carats of industrial and near-gem clian~onds.However, bull< 2.3 Mct of these from Austxaha, sampling of the remaining "meander belt1' deposits of the The U.S. Bureau of Mines extrapolatecl all current pro- center channel of the Birinl River has revealed Iower-than- duction figures in this report from laown prod~~ctionfor anticipated economic po~ential.ConsequentlyJ De Beers the year's first tluee qliarters. They reflect only official fig- decided to withdraw fro111 the project. ML/ ures rele~sedby the governments involved. MLJ

Virtual (iia~nondsby fax and on the Internet. Dilin~oncl GEM LOCALITLES Registry, Vol. 27, No. g1 1995! p. 2. Benitoite 'and joaq~~initein Arkansas. H. Barwoodl Mineral Potential buyers are warned to be very suspicious of unso- Newsl Vol. 11) No. 5, Mcly 1995' pp. 2' 5. licited e-n~~iiledor faxed offers for large q~lantitiesof rough The rare gel11 nineral benitoite, BaTiSi309, is foud in dia~nondsat discounted prices. When an offer seems too facet-grade pieces at the Gem Mine in San Renito CountyJ good to be true, it probably is: "Virhial diamondsfJ111:iy be CaMornia. Recentlyl it W:IS discovered at the Diamond Jo a ruse to find out a would-be buyer's Lwnk account n~unber. quarry in Magnet Cove, Arkansas. Three specimens have The offer illustrated here was for one million carats (!I of been found of clear l1s1

292 Ge~~~ologicalAbstracts GEMS & GEMOLOGY Winter 1995 the Mogok region of Myanmar. Once denigrated by gem Because m~myof the early diamond ininers were gold enth~~siastsas ~~s~ially being too dark, Mogolz sapphires are prospectors who just happelled on the diamonds, early recognized today 21s representing the full range of bl~ies, extraction techques were based on those that were SLIC- Some exceed 100 ct when cut. cessful for gold. However, the specific gravity of dian~ondis For the most part, the b1~1esapphes occur UI associa- only about 3.5, less than one-fifth that of gold, so palming tion with the rubies for which Mogolz is best Iznown, but a 'and wasl~u~gfor dainonds was inefficient. A horse-powered few localities yield primarily blue sapphires. The authors "puddler" conve~teddiamond-bearing dirt inlo a mixture of provide a map of the sapphe-prod~lcinglocalities near mud 'and boulders; the boulders were removed inanudly

Mo~ok.u and the mud sluiced into boxes, where the panning Famous large blue sapphires froin Mogolz ii~cludethe occurred. "Rich ground1'yielded abo~lt2 carats of dian~onds 958 ct rough "Genl of the J~~ngle,"which was fo~~i~din per cubic yard! roughly 4.5 diamonds per carat. Recorded 1929. It was cut into line stones, the largest of which production between the rus1Y.s beginning in 1872 and its weighed 66.53 ct. A 502 ct crystal (illus~ratedin t11e article) end in 1874 was about 600 carats. In 1883, further explo- of fine blue color ai~dslightly siky clarity was found in ration by Charles Rogers led the Australian Diamond 1994. Two tables list exceptional specimens of gel11 and Mining Company to resume operations. Various 19th-cen- nongein sapphire from sources worldwide. Among the tnry "pudding" n~achinesare described in this article, the nongeln specimens is a 63!000 ct crystal from Mogolz that first of a two-part series. Mu was unearthed around 1967, CMS Diamonds in South Australia. G. Clarlzsonl Austrafian Cat's-eye and asteriated gemstones from East Africa. N. R. Gold Gein ed Treasure, Vol. lol No. 5, May 1995, pp. Barot, G. Grazianai, E, Gubelin, and M. Rettiglueri, 27-29. Journal of Gern~~~ology~Vol. 24, No. 8, pp. 569-580. Alluvial dia~nondshave been found in the state of South The authors describe the characteristics of 19 assorted cha- Aus~ralia,and t11e geologic setting promises furlher dia- toyant or asteriated gemstones from East Africa, which has ~nonddiscoveries. Diamonds were first found at Ecllunga, become a sigruficant producer of such stones. Their samples near Adelaide, in 1839; by 1900, a total of 50 "salable" dia- include akxandrite, various garnets, apatite, aquainarine, n~onds11ad been recorded. Another fincl occurred in 1987. greenish yellow beryl, lzyanite, lEyre Peninsula (Jur:~ssiclumberlite pipes and Gold Gem ed Treasu~e~Vol. 10, No. 8, A~igust1995, dilzes, incl~iclingan altered n~onticclhtelumberlite com- pp. 21-22, 52, 54. plex), Tr~iro (Ordovicia~~la~nproites), Radi~~mHill The first report of diamonds in New South Wales' (Ordovician lamprophyre dil~es)~Port Augusta (micaceous A~istralia,was by E. H. Hargraves, who fou~dwhat were lu~nberlitesills), and M~~lgathing(mica-peridotite plugs and claimed to be diamonds at Reedy Creek, near Bathurst, in sills associated with lun~berlite].Exploration of solne of July 1851. Three ~nontl~slater, a dian~ondfroin the T~~ron these regions is under way. River was show11 to geologic s~~rveyorS. St~~cl~b~~ry, and six The article incl~~desa map of South Australia that diamonds were found in the tributaries of the Macquarie shows these localities and regional geologic structures. River in 1860. The fist comn~erciallyimportant di:unond MLl find was made in 1867 at Two Mile Flat, near the Cudgegoi~gRiver, west of Gulong. These alluvial diamonds Enleralds from Somondoco, Colombia: Chemical composi- were found in Tertiaty river gravels. Between 1867 and tion, fl~iidincliisions and origin. A. Ifault system. and cash ran OLI~.A diamond msh soon followed. For their study, the a~~thorsused electron microprobe,

Gen~ologicalAbstracts GEMS & CEIMOLOGY Winter 1995 293 enussion spectroscopy, and infrared absorptionl along with The reported benitoite occurrence hi Texas-doubtful. A. transmitted-light microscopy and thermogravimetxy, to Snuth1Mineral Newsl Vol. 1I, No. 5, May 1995, p. 5. analyzc the chemical composition and fluid incl~~sionsof The first edition of the Erlcj~clopedioo/Minerols by Roberts seven darlz green to near-colorless beryls froin one inine at et al. (1974)lists the Eocene sands of southwest Texas as a Achiote, Chivor/Somondoco. This testing was also done to source for benitoite. Mr. Smith c'm hdno evidence for ben- explain the growth conditions of the emeralds, itoite occhg there, however! and s~~geststhat the Backed by their analysis of the inclusionsl Kozlowslzi a~~thors(or an ~~ncitedprimary reference] nay have con- et al. argue that the beryllium-poor host roclzs contain fused benitoite with bentonite' an industrially important enough Be and Cr for the rich eincrald nuneralization at clay mineral lmown to occur in that area. MU Soino~~doco~and that the origin of the emeralds can be eas- ily explained by local migration processes. Thusl they dis- An unusual sapphjre-zircon-magnetitexenolith from the pute the hypotl~esisof 'm "endogenous deep seated source Clia~ithaburi gem province, Thailand. R. R. for berylli~ln~''proposed by A. A. B~LISand D. A. Mincev in Coenraads, P. Vicllit1 and F. L. Sutherlandl 1972. RT A4ineralogical Magazinel Vol 5g1 No. 1995/ pp. 465-479. Invcstnient in inining in India. H, Govindl Mining The geologic origin of Thadand's renowned gem corundum Magmine, Vol, 173, No. 1' July 1995, pp. 22-23. (sapphire and mby) and other gemstones (e.g.! zircon) asso- A new n~ineralspolicy anno~~ncedin Mach 1993 and leg- ciated with allcali basalts is problen~atic.Hence! any clue islated in 1994 selectively opened mining in India to partic- that might shed light on this subject wdl receive close ipation by foreign 'and domestic private investors. Relaxed scrutiny. This explains why such a detcded study was con- n~ininglaws and tax brealzs now mdze it easier for foreign ducted on a sinall (1.5 cm, 0.6 inch) xenolith found in tail- capital and expertise to help mine several nonf~lelre- ings from a mine near Khao Wua, about 7 lzm northwest of sources' incl~~dingdianlonds and gold. Chanthab~~ri. All new inining leases will be iss~ledfor a ininim~~mof The xenolith consists predoininantly of d~~minum- 20 years and a maxim~~mof 30. Existing leases now may be and titanium-rich octahedral magnetite that has exsolved renewed for 20 yearsl twice as long as previo~islyallowedl (brolcen down) into hercynitel nlagnetite'

GEMS & GEMOLOGY Winter 1995 in illegal inining, but women control 27 out of 121 ment proclucts rose 901000 ounces in 1974! to 39S1000 prospecting and mining licenses granted by the Zainbian ounces. MD governinent for aqu:~inarines~ainethysts, or en~eralds. Among the constraints on woinenls hll pxticip;ition in Sales of gold je\vehy up 6.3% in first half. M. I<. Golay/ ths sector are: lack of technical laowledge, diffic~~ltiesin Notional lewder, October 1, 1995) p, 26. clisciplining male e~nployees~time and inability constraints Gold jeweliy enjoyed its 14th consecutive quarter of sales due to fainhes) and social-cult~~ralattitudes. The authoi- increases in the sec011d quarter of 1995, accorhg to the recoininends that a revolving loan hind be set up to support World Gold Council. Total US. gold-jewelry ret'd sdes women ininersl and that assertiveness training be incl~~ded topped $3.8 billion m the first half of 1995 up 63% over the in the free technical training that the Z:~lnbiangoverilinent same period in 1994, Unit vol~~inel~~n~pecl even inore- already provides, ML1 9.4%-t0 inore than 43.6 inillion units. These res~~lts exceedecl the 5.2'X0 rise in U.S. retail sales ddng the same JEWELRY HISTORY period. Sales of gold jewelry were up across a11 retail distri- Head-dresses of the Tibetan Nyinba in Nepal. H. Gabriel) bution channels in the first half of 1995) ;iccording to the Arts of Asia) Vol. 25/ No. 4/ 1995) pp. 90-95. report, Discount stores continued to o~itperfor~nall other The intricgtely designed t(/iZzor is a large cereinoi~alhead- types; dollar sales went up ~ibout19Y0 as con~paredto the dress worn by the Nyinba people of Nepal for special occa- first half of 1994. Independent jewelry stores had an increase sions. It is part hat and part jewelry. Reflections of a faini- of 6.5% hl dollar sales. Chain jewelry stores n~atchedU.S. lyls wealth) these head-dresses are handed down from gen- retail sales with a 5.2% increase. Departlnent stores eration to generation. Many of them were bro~lglltfroin increased 3.8% over the first half of last year, However, cat- Tibet several centuries ago, wl~enthe ancestors of the alog showrooms lagged below thc category average, wlth Nyinba migrated to Nepal. Thusl they are seen as visible dollar sales LIP just 2.3% over the fmt half of 1994. evidence of the Tibetan roots of their owners. All ~nercl~andiseclasshcations had greater dollar sales Often, the upper side of this boat-shaped head-dress is ill the first half of 1995. Sales of earrings were LIP 13.9%; decorated yith turquoise, coral) pearls, goldl and silver. cllarinsl 15.9%; braceletsl 6.2%; and neclz chains, 3.2%. (Turquoisel however, is the most abundantly used gein Gold wedding rings, non-wedding ringsl and non-chain material here and in all Tibetan jewelry.] Less-opulent head- necldaces increased S.O'XO~9.4Y0) kind 5.6% (respectively) in cbesses contain brass cloines, The tuiZplatinum (I't), cop- ;~rticul;~teddetail, The relationship of the tuiZAlloy for- ination is a separate issue that does not affect l'n~bility.'~) PRECIOUS METALS The authors distinguish between the ability of a metal to form and brekilc bonds at the surface, and its ability to Platinu~ndein:~nd up 11% in 1994. M. K.Golay! Nutionl~l for111 new con~po~~ndsor be chssolved. TO loolz at bohdsl Jewelerl July 1) 1995, p. 30, they exainine bo~~clingbetween a hydrogen ~nolec~~le,H2, Demand for platinum was up 11 %-to :i record 4.5 1 d- and each metal. lion ounces-hl 1994 because of s~~bstantialgrowth in A second factor in "nobhty" is how tightly the d demand by the jewelry and a~~totnobileindustries, accord- orbitals are bound to the nucleus of the metal atonl. This ing to the Jolmson Matthey Cotnpany, Platin~~~ns~~pplies cleterlnines how easily metal-metal bonds break to n~alze rose 3%/ to 4.53 inillion ounces. Declining ship~nei~tsfroin co~npo~~ndswith other (non~netallic]elements, South Africa (down 6Y01 to 3.16 n~illionOLIIIC~S) were offset Au is I1noble1'in both respects) so it is the "n~ostnoble by a sizable jun~pin R~~ssiansales (LIP49Y0, to 1.01 inillion metal;'' Pt is "i~oble"with regard to coinpo~~nclforn~:ition. 0~111~es). It is a good metal for jewelry purposes, but acts as a catalyst The average price of platinum in 1994 was up 8%, to with H2 and other gases. Cu is noncatalytic but forms coln- $405.25 pet ouilce. Worldwide de~nandfor platin~t~njewel- pounds (eg1tarnishes) easily. Ni both shows catalytic activ- ry rose 7%) to 1.72 ndlion ouilcesl stimulated by Japatlls ity and can tarnish, increased fabrication of pure platii~u~njewehy. Growth ill This paper nicely introduces surface properties of imt- l~igll-technology and environn~ental applications was ah; howe&, some b:icl

Gen~ologicalAbstracts GKMS & GEMOLOGY Winter 1995 World silver demand exceeds supply in 1994. National Sin~ultaneouslyKro~itschoff in St. Petersburg, has got dia- jeweler, July 1, 1995, p. 30. mond crystals by a similar process." Demand for silver in 1994 exceeded the amount mined for This abstractor (MLJ)believes that the material pro- die fifth consecutive year, according to World Silver Survey, duced was probably silicon carbide, which was named a publication of the Silver Institute. The reported deficit was moissanite for "Moissan, in Paris" when it was later dis- 150.2 million ounces. covered in the Canyon Diablo meteorite (Dana's System of Silver has three major use categories-industrial/deco- Mineralogy, 7th ed., 1944, Vol. 1, pp. 123-124). ML/ rative, jewelry/silverware, and photography. The institute calls coins and medals a fourth category. Demand increased Diamonds grown from liquid at 1 atm. Diamond Industry in three of the four sectors, but worldwide fabrication Week, Vol. 2, No. 37, September 25, 1995, p. 1. demand actually declined 1,5%, or about 12 million ounces, during 1994. (Thearticle does not say which sectors Scientists at Pennsylvania State University have demon- are considered "fabrication" sectors.) This decline resulted strated that diamonds can be precipitated out of liquid- primarily from lower jewelry and silverware use in metal alloys containing dissolved carbon (up to 70%) and Thailand and India. Although this market segment saw its hydrogen. Alloys of iron, nickel, manganese, silver, gold, second highest demand level ever, it still declined 15% over and tin have been examined; diamond progressively precip- the all-time record year of 1.993, when India's use of silver itates out of the carbon-rich alloys as temperatures decrease for jewelry and silverware jumped over 100%. Total silver from about l,OOO°CTills opens the possibility of diamond supply dropped 3.9% in 1994. Mine production was down growth by the Czochralslu process. Mu 5% from 1993 to 1994 (468.8 million ounces to 444.2 mil- lion ounces). MD Ail examination of "serendipitous" synthetic zincite. R. C. Kainn~erling and M. L. Johnson, journal of SYNTHETICS AND SIMULANTS Gen~mology,Vol. 24, No. 8, pp. 563-568. Recently, gem-quality synthetic zincite was created by acci- AGEE hydrothern~alsynthetic emeralds. H. A. Hiinni and dent in ;I kiln used to produce zinc-based pint in Silesia, L. Kiefert, jewelSiam, Vol. 5, No. 5, 1994, pp. 80-85. Poland. Such material has been produced-also accidental- Tills article studies a relatively new synthetic emerald that ly-in the United States. Crystals and faceted stones of the appeared on the market in nlld-1994. After giving a short transparent Silesia material are being sold on the gem inar- history of flux- and hydrothermally grown emeralds, the ket. It ranges from medium light yellow through orange to authors describe their analysis of six so-called AGEE emer- dark reddish orange in color. Gemological properties are alds. The distributor, A G Japan Ltd [sic],says that its emer- consistent with (or very close to those for) natural zincite, a alds are actually Colombian rough that has been crushed rare material. However, the natural material is usually less into a fine powder, purified by lasers, and then hydrother- transparent and more brownish. In addition, chemical mally grown. The authors did not find any mineral inclu- analyses for natural zincite indicated niinor impurities of sions typical of natural emeralds (mica flakes, chromite Mn and/or Fe, whereas this synthetic zincite revealed only grains, tremolite needles), but they did find angular, Zn when analyzed with energy-dispersive X-ray fluores- chevron-shaped growth patterns, color zoning, and high cence (EDXRF), Electrical conductivity (observed in the chlorine concentrations (with the last probably the "most darkest-color sample) suggests that die color is due to band- secure" proof of a synthetic origin). The AGEE samples are gap absorption from defect states, not from Mn (ashas been similar to~butmore "impure" than-synthetic emeralds previously proposed). CMS produced by Biron International. The authors speculate that these synthetic emeralds might be lower-quality Biron syn- thetic emeralds that are being resold by A G Japan. [Editor's Kobe single crystal diamond update. Diamond Industry note: See related abstract in this issue-"Synthetic Week, September 25 1995, p. 1. Emeralds called AGEE. "1 CEA Kobe Steel, in Japan, has a process for growing single-crystal diamond thin films by chemical vapor deposition het- Can diamonds be manufactured? M]hg Journal, London, eroepit'axidly (i.e., on a nondiamond matrix). However, the June 2, 1995, p. 407. matrix required is single-crystal platinum, and there is still This historical note from the May 1895 Mining Jo~irz~al strain caused by the slightly different lattice sizes of plat- deserves to be quoted in its entirety: inum as compared to diamond. Single crystals of an iridi- "Can Diamonds be Manufactured! Professor F.W. um-platinum alloy might have a lower lattice mismatch, Clarke in an interview relative to the probable manufacture creating less strain and allowing the manufacture of larger of diamonds of marketable size stated that he entertained and more perfect synthetic diamond thin films. ML1 no doubt whatever on the matter, and that he firmly believed that this will be done soon. Moissan, in Paris, has Russians plan to produce diamond via explosive com- n~anufactureddiamonds by melting wrought iron together paction in unused wind tunnel. Diamond with carbon, and permitting the mixture to cool very slow- Depositions: Science 0) Technology, Vol. 5, No. 6, ly. Under these conditions the carbon became crystallised. 1995, pp. 9-10.

296 Gemological Abstracts GEMS & GEMOLOGY Winter 1995 hi nature, diamonds are produced in both static and dynain- Review (Summer 1983, Vol. 19, No. 3), traces the history of ic high-pressure environments, including (in the latter cate- American mining law from its roots in 9th-century Saxony gory) meteorite impacts. Russian scientists from the to court decisions in the 1980s. It contains much interest- Central Scientific Research Institute for Machine Building ing information. For example, rules for making mine claims intend to convert an unused wind tunnel at the TsNUMash were originally lenient; this encouraged trained workers, ballistic missile complex, in Kalinin, into a chamber for pro- and not serfs, to become-or stay-miners [a dangerous pro- ducing diamonds by dynamic means. fession). Miners had their own courts in 17th-century The 200-m-long, 0.5-m-wide chamber will be divided Cornwall and 1850s California. Mining law in the United into two segments by a steel disk; one side is evacuated, the Slates was developed largely because of, and to regulate, other filled with an explosive mixture of hydrogen and oxy- mining in California. Later, laws were added to handle more gen gases. Ignition of the gases rams the stainless-steel disk recent developments, such as oil fields (at first, by defining into a cast-iron target at speeds reaching 3.3 km per second them as large "lodes") and protection of the wilderness. (7,380 miles per hour), which converts trace amounts of car- MU bon in the cast iron into diamond particles. Yields of 15,000 carats per shotÑ0.8 wt.% of the cast-iron target-are pre- 1994: The geosciences in review. J. F. Gilbert et al., dicted. Future plans call for production of larger diamonds- Geotimes, Vol. 40, No. 2, February 1995, pp. 14-51. as much as 2,000 carats each-by means of an undefined This long review article summarizes recent developments iniprovenient in the process. MLJ in many fields of the Earth and planetary sciences. For gemologists, potentially relevant fields include metals and Synthetic emeralds called AGEE (in Japanese). Y. Kitawalu, mining, industrial minerals, exploration geochen~istry, Gemmology, Vol. 25, No, 303, December 1994, pp. niineralogy, mineral physics, metamorphic petrology, as 8-1 1. well as general geoscience information. In the field of met- Several years ago, synthetic emeralds that were commonly als and muling, the most notable development in 1994 was called AGEE in Japan started to appear in Japanese retail the availability of investment capital in North America, markets. They are distributed by A. G. Japan Ltd., who pro- which permitted bany companies to restructure their motes the stones as "powdered Colombian emeralds . . . debts and acquire newly privatized resources in Peru, hydrothermally recrystallized. . . [with]no color nor chem- Kazakhstan, and other countries. Diamonds are an indus- icals are added , . . ." This article, which includes six pho- trial niineral, and the boom (and later lowering of expecta- tos, reports on the gemological properties of 16 "AGEE" tions) in dianiond mining in Canada was noted. stones randomly selected from the stock of a retail store and Most geochemical exploration in 1994 was for gold and tested. Their color, size, and transparency were diverse. In diamonds. The most extensive was for lumberlite pipes (in fact, gemological tests revealed that the samples actually Africa, Canada, Australia, Brazil, Greenland, Guyana, represented four different types of synthetic emerald: Biron, Finland, and the U.S. [Colorado])and for alluvial dianiond vanadium beryl, Russian hydrothermal, and flux. The deposits (Ghana, Guinea, Mali, Namibia, Zaire, Brazil, author explains the characteristics of each type and warns Canada [Alberta], and Indonesia [Kalimantan]). readers to keep all types of synthetic emeralds in mind A niajor focus in mineralogy was the study of minerals when dealing with so-called AGEE stones. (Editor's note: and rocks at high pressures, including investigation of the See related abstract in this issue-"AGEE Hydrothermal subcontinental lithosphere through- examination of xeno- Synthetic Emeralds."] HN liths and investigation of residual phases from high-pressure nietan~orphicassemblages containing coesite. In mineral MISCELLANEOUS physics, a symposium at the ~aliforniaInstitute of Technology discussed the origin and fate of volatiles (espe- The miners law. J. L. Neff, Part I-California Geology, Vol. cially water) in the deep mantle. Recently developed tecli- 47, No. 6, 1994, pp. 152-158; Part D-California niques in nietaniorphjc petrology make it possible to date Geology, Vol. 48, No. 1, 1995, pp. 10-21. metaniorphmn directly using Sin-Nd, Rb-Sr, and U-Pb iso- Most nIllUng in the United States is governed by the Federal topes in garnet-bearing rocks, including eclogites. The tim- Act of May 10, 1872, which permits claims to a length of ing of the growth of porphyroblasts, relative to deformation "vein, ledge, or lode," together with a specific area on each times, may be possible; this line of study could lead to new side of the vein. This act is controversial today for a num- understanding of the origin and emplacement of eclogitic ber of reasons. One is that no royalties are paid to the feder- diamonds. al government for claims made on federal land. A second is As for information science, the average geoscience that the law has been (ab)used as a means to claim land on book published in the United States in 1994 cost $66 (with which to build houses rather than mines. books published in continental Western Europe costing This long article, originally published in the Idaho Law nearly $150 per title). MLl

Gemological Abstracts GEMS & GEMOLOGY Winter 1995 NUMBERS 1-4 1995

SUBJECT INDEX This index gives the first author (in parentheses), the issue, and the first page (plus "ffl')of the article in which the indexed subject occurs. For Gem News (GN),Gem Trade Lab Notes (GTLN),and Letters (Let)sections, inclusive pages are given for the subject item. The reader is referred to the Author Index at the end of this section for the full title and the coauthors. where appropriate, of the articles cited. The pages covered by each issue are as follows: Spring (1-86). Summer (87-148). Fall (149-226), and Winter (227-304).

Asterism (Diamantmuseurn Anwerp] diffusion-induced,in ruby W95:288 Africa (GTLNJSu95:126; in sapphire Standard Catalog of Gezn "deep" quartz from [GTLN)Sp95:56-57 Values, 2nd ed. (Miller and (GN]F95:208-209 Six-rayed star in emerald Sinkankas] F95:217 history of diamond sources in (GN)F95:206 Botswana (Janse]W95:228ff Australia history of diamond sources in Alexandrite rubies from the Barrington vol- (Janse)W95:228ff fracture-filled, with high R.I. canic shield. East Australia Brazil (GTLNlF95: 196 (GN)W95:281-282 parti-colored fluorite from with pleochroic twinned growth Azurite, see Rocks (GN]Su95:131 zones (GTLN)Sp95:52 Burma, see Myanmar synthetic flux-grown (GTLN)F95:196; from Russia 8 (GN)W95:285 Baja California, see Mexico c Amazonite Basalt Calcareous concretions (non- from Russia (GN)Sp95:63-64 sapphire- and zircon-bearing, in nacreous pearls] unusual speci- see also Feldspar central Nigeria (Letters)Sp95:1 mens of (GN)W95:280-281 Amber Beryl Calcite inclusions in (GN]W95:275 green, from Central Nigeria "rainbow" [GTLN)Su95:130 Amber simulant (GN]W95:275-276 Canada natural resin in plastic red, from Utah (GN]W95:276 freshwater natural pearls from (GN)Su95:134-135 from the Ukraine (GN)Sp95:68 the Lac St. Jean area, Quebec Amethyst see also Emerald (GN)W95:280 synthetic, from Russia, with Book Reviews sphalerite and other gems from unusual color zoning Diamond Exploration into the (GN]Sp95:65-67 [GN)F95:213-214 21st Century (Griffin, Ed.) synthetic diamonds misrepre- see also Quartz F95:217 sented as rough from Andradite, see Garnet Fancy-Color Diamonds [Harris) [GN)Su95:129 Angola Su95: 141; comments on review Carving, see Lapidary Arts history of diamond sources in of (Letters]F95: 150-15 1 Cat's-eye, see Chatoyancy [Janse)W95:228ff Gems, Their Sources, Central African Republic Antlerite, see Rocks Descriptions and history of diamond sources in Apatite Identification, 5th ed. (Janse)W95:228ff from Madagascar (GN)Sp95:60; (Webster, rev. by P. Read] Chatoyancy cat's-eye (GN]F95:205-206 Sp95:76 in emerald from Brazil Aquamarine Hey's Mineral Index, 3rd ed. (GN)Sp95:60-61 from Nigeria (GNJSu95:129 (dark]Sp95:76 in sapphire (GTLN]Su95:126-127 Assembled stones The New Alchemists: Breaking Chemical con~position "constructs" of natural and syn- Through the- Barriers of High of gross~~lar-anclraditegarnet thetic quartz (GN)F95:216 Pressure [Hazen)F95:217 from Mali (JohnsonJF95:152ff jadeite and plastic Photo Masters for Diamond of rubies from Mong Hsu. (GTLNJF95:199-201 Grading (Roskin)W95:288 Myanmar (PerettiISp95:Tff topaz triplet resembling Paraiba A Sparkling Age, 17th-century China tourmaline (GTLN]W95:272 Diamond Jewellery gem localities in (GN)W95:276

298 Annual Index GEMS & GEMOLOGY Winter 1995 Citrine, see Quartz, synthetic mining, in Russia of synthetic ruby, to induce "fin- Clinochlore (GN)F95:204-205 gerprint" inclusions and aster- color-change, from Russia offshore prospecting ship ism (GTLNJSu95:126 (GN)Su95:129-130 (GN)F95:205 Dolomite, see Rocks Coating Diamond, colored Donors of beryl with plastic to simulate black, with iron (GTLN)W95:266 "Thank you" Su95:140 emerald (GTLNJF95:199 green, with color caused by Doublets, see Assembled stones Coated glass beads imitating inclusions (GTLNJF95:197 Dyeing black pearls (GTLNJF95: treated pink of nephrite (GTLN)Sp95:55 202-203 (GTLNJSu95:121-122 of quartzite to imitate jade Color, cause of Diamond, cuts and cutting of (GTLNJSu95:125-126 c03+in synthetic green star sap- "Context" and "Spirit Sun" cuts phire (GTLN)Sp95:57-58 (GN)Sp95:59-60 E in pink freshwater pearls, red Diamond, inclusions in Editorials coral (GN)W95:276-277 as cause of green face-up color 1995 Challenge Winners in rubies from Mong HSLI, (GTLNJF95:197 (KellerJF95:149 Myanmar (Peretti)Sp95:2ff fluid (GN)W95:274 Russia Reemerges as a Gemstone in synthetic "Ti-sapphire" from iridescence in incompletely filled Giant (Liddicoat)Su95:87 Union Carbide fracture (GTLN)F95:198 Diamond Prospecting and (JohnsonJF95:188ff "mobile" diamond (GN]F95:204 Market Prospects Color change natural features resembling char- (Liddicoat)W95:227 clinochlore from Russia acteristics of fracture filling Egypt (GNJSu95:129-130 (GTLN)Sp95:52 green quartz from (GN]F95:209 sapphire from Tanzania strain phantom (GTLNJSu95:120 "Eilat" stone, see Rocks (GNJSp95:64-65 triangular growth features Emerald in synthetic sapphire (GTLN)Sp95:53 from Central Nigeria (GTLN)Su95:127 use of, to separate synthetic from (GN)W95:275-276 zircon (GN)F95:212-213 natural diamond chatoyant, seen at Tucson shows Color zoning (Shigley]W95:256ff (GN)Sp95:60 in rubies from Mong Hsu, Diamond, synthetic fracture filling of (GTLN)Sp95:54 Myanmar (Peretti]Sp95:2lf chart for separation from natural from India (GN)W95:277 in synthetic amethyst from (Shigley)W95:256ff necklaces of, fashioned in India Russia (GN)F95:213-214 magnet for testing of (GN) (GN)Sp95:61 Cordierite, see Iolite Sp95:69 with six-rayed star (GNJF95:206 Corundum misrepresented as Canadian trapiche, seen at Tucson shows diffusion-treated rough [GN)Su95:129 (GN]Sp95:60-6 1 [GTLN]F95:196-197 suite (GTLN)Su95:122-123 from the Ural Mountains, Russia see also Ruby, Sapphire treated-color red [LaskovenlzovJSu95: 106ff; Corundum sim~ilant (GTLN]Sp95:53-54 (LettersJF95:150 crystals simulated by GGG Diamond, treatment of see also Beryl (GNJW95:285-286 fracture-filled with thallium Emerald sim~~lant Corundum, synthetic (GTLN)W95:266 plastic-coated beryl "recrystallizecl" (GNJSu95: fracture filling, chart and identi- (GTLNJF95:199 135-136; laser inscription of fication of (McClure) Emerald, synthetic (GNJSu95:136-137 Su95:114ff; firms processing "recrystallized" (GN)Sp95:71 see also Ruby, synthetic; (GN)Su95:129 Russian (CN)Sp95:71 Sapphire, synthetic iridescence in incompletely filled laser inscription of Cubic Zirconia fracture (GTLNJF95:198 (GN)Su95:136-137 from Russia (GN)Sp95:70 irradiated old mine cut Enhancement Cuts and cutting (GTLN)Sp95:53 see Coating, Diffusion treatment, see Diamond, cuts and cutting natural features resembling char- Filling, Heat treatment, of; Lapidary arts acteristics of fracture filling Treatment (GTLN]Sp95:52 Erra turn D pink (GTLN)Su95:121-122 to "Gem Corundum in Alkali Diamond synthetics treated to create red Basalt" (Letters)Sp95:l chart for separation from syn- color (GTLNJSp9553-54 to Gem Trade Lab Notes of Fall thetic [Shigley)W95:256ff Diaspore issue (GTLN)W95:273 crystal with etched hole from Turkey (GNJSp95:60 Ethiopia (GTLN)Su95:122 Diffusion treatment opal from (GNJSu95:132 historical trends in the industry of corundum to imitate ruby (GN)W95:274-275 (GTLNIF95:196-1 97 history of sources in Africa of sapphire, to induce asterism F (Janse)W95:228ff and purple color (GTLN) Faceting machine measurement of color Sp95:56-57; seen at the Tucson see Diamond, cuts and cutting (Letters)F95:15 1 shows (GN)Sp95:71 of; Lapidary arts

Annual Index GEMS & GEMOLOGY Winter 1995 299 Fakes Glass (GTLN)Su95:122-123 GGG fashioned to simulate coated beads imivating black twin lamellae in synthetic sap- corundum crystals pearls (GTLN]F95:202-203 phire (GTLN)Su95:127 (GN)W95:285-286 as green jadeite simulant 1ndia- synthetic diamonds misrepre- (GTLN)F95:201 emeralds from (GN)W95:277 sented as Canadian rough as "Mexican" opal simulant iolite and other gems from Orissa (GN)Su95:129 (GTLN)F95:201-202 (GN)Sp95:62 Feldspar natural, seen at the Tucson phenomenal feldspar from dyed to imitate lapis lazuli shows (GNJSp95:61 (GN)Su95:130-131 [GTLN)F95:201 partially devitrified, as jadeite Infrared spectroscopy, see phenomenal, from India simulant (GNJSu95:137 Spectroscopy, infrared (GN)Su95:130-131 tektites (GN)W95:277-278 Instrumentation see also Amazonite, Rocks GOrgeyite Brewster angle refractometer Fibrolite, see Sillimanite from Russia (GN)Su95:129-130 [GN)W95:287 Filling, fracture or cavity Grossular, see Garnet inclusion-viewing system of alexandrite (GTLN)F95:196 (GN)Sp95:69 of diamond, chart for identifica- machine measurement of dia- tion of [McClure)Su95:114ffj mond color (Letters)F95:151 firms processing Hausmannite magnet for testing synthetic clia- (GN)Su95:129; incomplete, drusy [GN]F95:207-208 monds (GN]Sp95:69 with iridescence Heat treatment new spectrometer [GN)Su95:139 (GTLN]F95:198; natural fea- of rubies from Mong Hsu, International Gemmological tures resembling (GTLN) Myanmar (Peretti)Sp95:2ff Conference (1CG) Sp95:52; with thallium Hematite highlights of the 25th, held in (GTLN]W95:266 "rainbow" (GN)Sp95:61-62 Bangkok, Thailand of emerald (GTLN)Sp95:54 simulated by iridescent shale or (GNJW95:274ff of star ruby (GTLN)W95:270 slate (GN)Su95:137 Iolite Flash effect tHollandine" (spessartine), see from Madagascar (GN)Sp95:62 in diamond (McClure)Su95:114ff; Garnet from Orissa, India (GN)Sp95:62 almost masked by body color Israel (GTLN)W95:266 I "Eilat" stone from (GN)F95:206 in emerald (GTLN)Sp95:54 Inclusions Fluorescence, ultraviolet in amber and other gems J use of, to separate synthetic from [GN)W95:275 natural diamond causing chatoyancy in sapphire Jade (Shigley)W95:256ff (GTLN)Su95:126-1 27 market in Mandalay, Myanmar see also Luminescence dendrite (with flux-like appear- (GN)W95:278-279 Fluorite ance] in natural spinel museum in Costa Rica parti-colored, from Brazil (GTLN)Sp95:58 (GN)F95:208 (GN)Su95:13 1 diffusion-induced "fingerprints" "violet jade" containing jadeite Fourier-transform infrared spec- in synthetic ruby (CN)W95:276-277 troscopy (FTIR),see (GTLN)Su95:126 see also Jadeite, Nephrite Spectroscopy, infrared in frac~ure-filleddiamonds Jade simulants (McClure)Su95:1 14ff dyed quartzite G goethite and lepidocrocite in (GTLN)Su95:125-126 "strawberry" quartz from glass (GTLN)F95:201 Gadolinium gallium garnet (GGG) Russia (GN)Sp95:63-64 partially devitrified glass fashioned to simulate a corun- growth banding in grossular- (GN)Su95:I37 dum crystal (GN)W95:285-286 andradite garnets from Mali rock resembling jadeite Garnet (JohnsonJF95:152ff (GTLN)W95:268-269 grossular-andradite, from Mali hematite-like in quartz Jadeite (GNJSp95:61; (GN)F95:209-2 I0 assemblage with plastic (Johnsoii)F95:152ff hogbomite in spinel (GTLNIF95:199-20 1 spessartine, from Namibia (GTLN)W95:272 bleached and impregnated (GN)Su95:134 magnetite in serpentine (GTLNJSp95:55 Gem carving, see Lapidary arts (GTLN)W95:271-272 with misleading inclusions Gem collections, see Museums phantom planes in zircon [GTLN)Su95:123-124 Gems ei) Gemology (GTLN)W95:273 with a mounting adhesive that Challenge, Sp95:74-75 in rubies from Mong Hsu, falsely suggested polymer Most Valuable Article Award, Myanmar (Peretti)Sp95:2ff impregnation (GTLN)W95:267 Sp95:72-73 in sapphires from southern lapidaries in Myanmar wins two ASAE Gold Circle Vietnam [Smith]F95:168ff (GN]W95:279-280 awards (GN)W95:287 in sapphires from Yogo Gulch, unusually thin carving Genthelvite Montana (Mychaluk)Sp95:28ff (GTLN)W95:266-267 faceted (GN)F95:206-207 in synthetic diamond in "violet jade"

300 Annual Index GEMS & GEMOLOGY Winter 1995 (GN)W95:276-277 Mali green beryl and emerald from Jewelry grossular-andradite garnet from (GN)W95:275-276 gems in ancient jewels (GN)Sp95:61; large aquamarines from (GN)W95:287 (Johnson]F95:152ff (GN)Su95:129 "Mandarin" garnet (spessartine), see North Carolina, see United States Garnet Manganotychite Kaliborite - 0 from Russia (GN)Su95:129-130 from Canada (GN)Sp95:65-67 "IOlivine, see Peridot Kyoccra Meteorites Omphacite, see Rocks plastic-impregnated synthetic seen at the Tucson shows Opal opal manufactured by (GN)Sp95:62-63 carved (GN)Su95:131-132 (GN)Su95:137-138 see also Glass from Ethiopia (GNJSu95:132 Mexico green, from Serbia (GN]F95:208 history of pearl-oyster culturing Opal simulant L in South Baja California glass, as "Mexican" Labradorite, see Feldspar (Cari1io)Su95:88ff (GTLN]F95:20 1-202 Laos natural gray blister pearl from Opal, synthetic sapphire mining in Baja California plastic-impregnated, manufac- (CN)W95:282-283 (GTLN)Sp95:55-56 tured by Kyocera Lapidary arts Meyer H. 0. A. (GNISu95:137-138; carving of meerschaum obituary (LetterslF95:15 1 (GTLN)W95:267-268 sepiolite) in Turkey Microscopy Origin of gems (Sariiz]Sp95:42ff nuclear, of rubies (GN)W95:286 sapphires, in basalts carved opal (GNISu95:131-132 video-monitoring system for (Letters)Sp95:ljat Yogo Gulch, jadeite lapidaries in Myanmar (GN)Sp95:69 Montana (Mychal~ik)Sp95:28ff (GN)W95:279-280 Mining Orthoclase, see Feldspar machine cutting of calibrated of diamonds in Africa gems by Swarovski (Janse)W95:228ff P (CN]Sp95:67-68 of emeralds from the Ural as a source of gemological infor- Paraiba, see Tourmaline Mountains, Russia Pearl mation (GN)W95:286 (LaslPinctada maza tlanica sapphire from N pearl and mother-of-pearl oyster (GN)Su95:132-133; from the Gulf of Mexico (GN]W95:283-284 Namibia (Carifio)Su95:88ff Magnet history of diamond sources in "Platigen~" for testing synthetic clia- (Janse)W95:228ff platinum alloy used as gem monds (GN)Sp95:69 spessartine from (GN)Su95:134 material (GN]Su95:138-139 Malachite Nephrite Pleochroism impregnation with epoxy resin dyed green (GTLN)Sp95:55 in twinned alexandrite (GN)F95:213 Nigeria (GTLN)Sp95:52

Annual Index GEMS & GEMOLOGY Winter 1995 Poland (Peretti]Sp95:2ff; (Mychal~1k]Sp95:28ff synthetic zincite from (GN)F95:210-211 with zoned transmission lumi- (GN)Sp95:71 from North Carolina nescence (GTLN)W95:270-271 Preobrazhenskite (GN)F95:211 see also Corundum from Russia (GN)Su95:129-130 nuclear microscopy of Sapphire, synthetic Pteria sterna [GNJW95:286 with color altered by UV radia- pearl and mother-of-pearl oyster star, with color zoning tion (GTLNJW95:271 from the Gulf of Mexico (GTLN)W95:270;with cavity color-change, with twin lamellae (Carifio)Su95:88ff filling (GTLN)W95:270 (GTLN)Su95:127 see also Corundum Czochralslzi-pulled blue Q Ruby, synthetic (GN)F95:214-215 Quartz with diffusion-induced "finger- green star (GTLN)Sp95:57-58 print" inclusions and asterism "constructs" of natural and syn- pink, by Kashan (GN)Sp95:70j thetic (GN)F95:216 (GTLN)Su95:126 "recrystallized" (GN)Sp95:71, "deep" from Africa by Kashan (GN)Sp95:70 Su:135-136 [GN)F95:208-209 "recrystallized" (GN)Sp95:71 "t;inztinitel'-colored unusually large (GTLN]F95:203 green, from Egypt (GN)F95:209 [GN)F95:215-216 Russia with hematite-like inclusions Ti-sapphire" from Union color-change clinochlore from (GN)F95:209-210 Carbide (Johnson)F95:188ff (GN]Su95:129-130 "strawberry" from Russia Scapoli te diamond mining in (GN)Sp95:63-64 purple, from Tajikistan (GN)F95:204-205 see also Amethyst, Rocks (GN)F95:211-212 emeralds from the Ural Quartz, synthetic from Sri Lanlza Mountains "constructs" of natural and syn- (GN)W95:284-285 (LaskovenkovJSu95:106ff thetic (GN)F95:216 Sepiolite gorgeyite from green and yellow bicolor see Meerschaum (GN)Su95:129-130 (GTLN)W95:268 Serandite Quartzite kaliborite from from Canada (GN)Sp95:65-67 (GN)Su95:129-130 dyed to imitate jade Serbia preobrazhenskite from (GTLN)Su95:125-126 green opal from (GN)F95:208 (GNJSu95:129-130 Serpentine significance to gem market magnetic (GTLN]W95:271-272 R (Ed)Su95:87 Shell 'strawberry" quartz and other Refractive Index "coconut pearls" from Indonesia gems from (GN)Sp95:63-64 (GN)W95:280-281 Alexandrite with high R.I., frac- synthetic alexandrite from ture filled (GTLNIF95:196 used for mother-of-pearl in South (GN)W95:285 Baja California Ruby with high R.I.'s synthetic emerald from (GTLN)W95:269-270 (CariiioJSu95:88ff [GN)Sp95:71 Shortite Resin synthetics and simulants from aromatic, possibly myrrh from Canada (GN)Sp95:65-67 (GN)Sp95:70 Sillimanite (GN)F95:210 see also Tajikistan Rocks from Orissa (GN)Su95:130 azurite, antlerite, and quartz Skarn (GTLNjSu95:120 from Russia (GNJSp95:63-64 dolomite and quartz, resembling Sapphire South Africa jadeite (GTLN)W95:268-269 cat's-eye (GTLN)Su95:126-127 history of diamond sources and "Eilat" stone from Israel and diffusion-treated (GN)Sp95:71 mining operations in Peru (GN]F95:206 with diffusion-induced star and (Janse)W95:228ff jadeite-containing "violet jade" purple color Spectra, visible range (GN)W95:276-277 (GTLN)Sp95:56-57 of grossular-andradite garnet omphacite and feldspar carving from Madagascar from Mali (Johnson)F95:152ff (GTLN)Su95:124 (GNJSu95:132-133; of rubies from Mong Hsu, slzam from Russia (GN)W95:283-284 Myanmar (Peretti)Sp95:2ff (GN]Sp95:63-64 mining in Laos of sapphires from southern Ruby (GN)W95:282-283 Vietnam (Smith)F95:168ff from East Australia n~iscellaneousnotes on spectrometer to improve resolu- (GN)W95:281-282 (GN)Sp95:64 tion of (GN)Su95:139 with high .R.I.'s from North Carolina of synthetic "Ti-sapphire" from (GTLN)W95:269-270 (GN)F95:211 Union Carbide imitated by diffusion-treated from Tanzania (GN)Sp95:64-65, (JohnsonJF95:188ff corundum (GTLN)F95:196-197 Su95: 133-134 Spectroscopy, infrared market in Taunggyi, Myanmar from southern Vietnam of rubies from Mong Hsu, (GN)W95:282 (SmithJF95:168ff Myanmar (PerettiJSp95:2ff from Mong Hsu, Myanmar from Yogo Gulch, Montana of sapphire from southern

302 Annual Index GEMS & GEMOLOGY Winter 1995 Vietnam (Sn1ith)F95:168ff Topiiz Gulch (Mychaluk)Sp95:28ff Spectroscopy, Raman triplet resembling Paraiba tour- North Carolina, ruby and sap- geniological applications of maline (CTLN)W95:272-273 phire from (GN)F95:211 (GN)W95:286-287 from the Ukraine (GN)Sp95:68 Utah, red beryl from of miscellaneous gems at CIS- Tourmaline (GN)W95:276 GEM laboratory seen at the Tucson shows Utah, see United States (GN)W95:276-277 (GN)Sp95:68-69 Spessartine, see Garnet Tourmaline simulant v Sphalerite topaz triplet resembling Paraiba Vietnam from Canada (GN)Sp95:65-67 tournlaline sapphires from southern part Spinel (GTLN)W95:272-273 (Smith)F95:168ff with dendrite inclusion Treatment (GTLN)Sp95:58 bleaching and impregnation of x with hogbomite inclusions jadeite (GTLN)Sp95:55 X-radiography (CTLN)W95:272 epoxy-resin impregnation of of damaged nucleus in cultured from Tajikistan (GN)F95:212 malachite (GN)F95:213 pearl (GTLNJSu95:125 Sri Lanka plastic impregnation of Kyocera of natural blister pearl from Baja scapolites from synthetic opal California (GTLN)Sp95:55-56 (GN)W95:284-285 (GN)Su95:137-138; Star, see Asterism; Emerald; lGTLN)W95:267-268 z Ruby; Sapphire, synthetic see also Coating; Diamond, treat- Zaire Synthetics ment of; Diffusion treatment; history of diamond sources in "recrystallized" (GN)Sp95:71 Dyeing; Filling; Heat treatment (Janse)W95:228ff from Russia (GN)Sp95:70 Tucson gem and mineral shows Zimbabwe see also specific gem materials announcements for 1996 history of diamond sources in Sugili te lGN)F95:216 (Janse)W95:228ff from Canada (GN)Sp95:65-67 highlights of (GN]Sp95:59ff Zincite Swaziland unusual gems seen at synthetic, from Poland history of diamond sources in lGN)Su95:130 (GN)Sp95:71 (Janse)W95:228ff Turkey Zircon meerschaum (sepiolitc) from color-change (GN)F95:212-213 T Eskisehir Province, Turkey with phantom planes (Sariiz]Sp95:42ff (GTLN)W95:273 Tajikistan diaspore from (GN)Sp95:60 Zoisite purple scapolite from from Merelani, Tanzania (GN)F95:211-212 (GN)W95:285 spinel from (GN)F95:212 u tanzanite simulated by synthetic Tanzania Ukraine sapphire (GN)F95:215-216 sapphires from (GN]Sp95:64-65; topaz and beryl from Zoning and other gems from (GN)Sp95:68 growth planes in zircon (GN)Su95:133-134 Union Carbide (GTLN)W95:273 tanzanite and other zoisites from synthetic "Ti-sapphire" from growth zoning in grossular- Merelani (GN)W95:285 (Johnson)F95:188ff andradite garnets from Mali Tanzanite, see Zoisite United States (JohnsonJF95:152ff Tektite, see Glass Montana, sapphires from Yogo growth zoning in Mong Hsu ruby

Annual Index GEMS & GEMOLOGY Winter 1995 303 AUTHOR INDEX

This index lists, in alphabetical order, the authors of all articles that appeared in the four issues of Volume 31 of Gems Q) Gemology, together with the inclusive page numbers and the specific isssue [in parentheses). Full citation is provided under the first author only, with ref- erence made from joint authors.

B P Bernhardt H-J., see Peretti A. Kammerling R.C., see McClure Peretti A., Schmetzer K., Boehn~E., see Johnson M.L. S.F., Johnson M.L., Smith C.P. Bernhardt H-J.,Mouawad F.: Keller A.S., see Smith C.P. Rubies from Mong Hsu, 2-25 c Khoa N.D., see Smith C.P. (Spring) Carifio M., Monteforte M.: Krupp H., see Johnson M.L. Peretti A., see Smith C.P. History of Pearling in La R Paz Bay, South Baja California, L 88-105(Sumn1er) Reinitz I., see Shigley J.E. LaslYogo Sapphire Zang J.W.,see Johnson M.L. Union Carbide, 188-195 (Fall) Deposit, 28-41 [Spring) Zhernakov V.I., see Laskovenkov A.F.

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304 Annual Index GEMS & GEMOLOGY Winter 1995