Gems&Gemology

VOLUME XXII SUMMER 1986

~e quarterly journal of the Gemological Institute of America SUMMER 1986 Volume 22 Number 2

Gems&Gemology

TABLE OF CONTENTS

FEATURE The Coscuez Mine: A Major Source of Colombian ARTICLES Ron Ringsmd The Elahera Gem Field in Central Mahinda Gunawardene and Mahinda S. Rupasinghe

NOTES Some Unusual Sillimanite Cat's-Eyes AND NEW ' E. Giibelin, M. Weibel, and C. R. Woensdregt TECHNIQUES An Examination of Four Important Gems C. W. Fryer and John I. Koivula Green Glass Made of Mount Saint Helens Ash? Kurt Nassau

REGULAR Editorial Forum FEATURES Gem Trade Lab Notes Gem News Gemological Abstracts Book Reviews Suggestions for Authors

ABOUT THE COVER: Currently one of the most productive, if little known, mines in is the Coscuez mine. The 14.52-ct emeraldillustrated here shows the highly saturated bluish green color that is characteristic of emeralds from this locality, which lies only 10 kmfrom the famous mine. Ron Ringsrud's articlein this issue takes a comprehensivelook at Coscuez, its history, geology, mining activities, and the emeralds found there. Photo C 1986 Harold el Erica Van Pelt-Photographers, Los Angeles, CA.

Typesetting for Gems &. Gemology is by Scientific Composition, Los Angeles, CA. Color separa- tions are by Effective Graphics, Compton, CA. Printing is by Waverly Press, Easton, MD.

@I986 Gemological Institute of America All rights reserved ISSN 001 6-626X SUMMER 1986 Volume 22 Number 2

EDITORIAL Editor-in-Chief Editor Editor, Gem Trade Lab Notes STAFF Richard T. Liddicoat, jr. Alice S. Keller C. W. Fryer Associate Editors 1660 Stewart St. Editor, Gemological Abstracts Santa Monica, CA 90404 Peter C. Keller Dona M. Dirlam D. Vincent Manson Telephone: (213) 829-299 1 John Sinkankas Assistant Editor Editor, Book Reviews Technical Editor Sally A. Thomas Jeffrey M. Burbank Carol M. Stockton Subscriptions Contributing Editor and Janet M. Fryer, Manager Editor, Gem News Lisa Hebenstreit, Assistant Manager John I. Koivula

PRODUCTION Art Director Production Assistant Production Assistant STAFF Linda Manion Cecile Miranda Patricia Mayer

EDITORIAL Robert Crowningshield Anthony R. Kampf Kurt Nassau REVIEW BOARD New York, NY Los Angeles, CA BernaidsviIIe, Nf Pete Dunn Robert E. Kane Glenn Nord Washington, DC Los Angeles, CA Los Angeles, CA Dennis Foltz John Koivula Ray Page Santa Monica, CA Santa Monica, CA Santa Monica, CA Chuck Fryer Henry 0. A. Meyer George Rossman Santa Monica, CA West LaFayette, Indiana Pasadena, CA C. S. Hurlbut, Jr. Sallie Morton James E. Shigley Cambridge, San lose, CA Sunta Monica, CA

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MANUSCRIPT Gems a> Gemology welcomes the submission of articles on all aspects of the field. Please see the Suggestions for Au- SUBMISSIONS thors in this journal, or contact the editor for a copy. Letters on articles published in Gems dGemology and other relevant matters are also welcome. COPYRIGHT Abstracting is permitted with credit to the source. Libraries arc permitted to photocopy beyond the limits of U.S. copyright law for private use of patrons. Instructors are permitted to photocopy isolated articles for noncommercial AND REPRINT classroom use without fee. For other copying, reprint, or republication permission, please contact the Editor. PERMISSIONS Gems a> Gemology is published quarterly by the Gemological Institute of America, a nonprofit educational organization for the jewelry industry, 1660 Stewart St., Santa Monica, CA 90404. Application to mail at second class postage rates is pending in Santa Monica, CA 90404 and at additional mailing offices. Postmaster: Return undeliverable copies of Gems aJ Gemology to 1660 Stewart St., Santa Monica, CA 90404. Any opinions expressed in signed articles'are understood to be the views of the authors and not of the publishers. THE COSCUEZ MINE: A MAJOR SOURCE OF

By Ron Ringsrud

The Muzo emerald district, in Boyacd, henever fine emeralds are discussed in the gem Colombia, contains several mines. w trade, the term Muzo is invariably used to describe Although the Muzo mine is undoubtedly the best. Yet Colombia's Muzo district actually the best known, the Coscuezmineis rapidly encompasses several mines, of which two are currently gaining significance as a major source of major producers: Muzo and Coscuez. Many stones prop- fine emeralds. Yet few in the trade outside erly referred to as "Mum emeralds" actually come from of Colombia are aware of the importance of Coscuez (figure I), which lies only 10 km from the Muzo Coscuez orJznow about the emeralds mined 2). there. The '~oscuezmine is literally mine (figure Although smaller than Muzo, the Coscuez hundreds of years old, and its history is mine has for more than 300 years produced some of the closely tied to that of Muzo, Located only best emeralds from the Muzo region, at times in quantities about 10 lzm apart, the two areas also share that have even surpassed the Muzo mine. many geologic features and both are Five years ago, Gems o) Gemology published an article currently exploited using open-cut mining outlining the history, geology, and production of Colom- methods. The Cosczzez emeralds are similar 's two major emerald-mining regions: Muzo and to Muzo stones in their physical properties, (Keller, 198 1). Soon after that article appeared, however, but they occurin a somewhat broaderrange production from the Chivor region began to fall, while that of hue and saturation. Prospects for even from the Coscuez mine accelerated rapidly. During this greaterproduction at Coscuez in the future same period, the Muzo mine continued to supply good are good. quantities of emeralds. Today, most of the emeralds mined in Colombia come from the Muzo district, and the Cos- cuez mine has grown to become the second largest pro- ducer of emeralds in Colombia. Yet in spite of its prominence, little has been written ABOUT THE AUTHOR specifically on Coscuez or the Coscuez emeralds in the Mr. Ringsrud is a major partner in Constellation jewelry and gemology literature, and few in the trade out- Gems, Inc., an import firm specializing in Colombian emeralds, which is headquartered in side of Colombia are aware of its importance as a major Los Angeles, California. source of fine emeralds. In March 1984, the author traveled Acknowledgments: The author would like to thank to Coscuez in the company of local dealers; two years later, the following people for their assistance in in May 1986, he revisited the mine as a guest of Colombian researching and completing this article: Samuel, Mines Co., a major stockholder of ESMERACOL, the pres- Amnon, and Albert Gad; Jack and James Rotlewicz; Jorge Rozo; Eileen Weatherby; Gabriel Acufia; Dr. ent leaseholder of the Coscuez mine. Based on information Alfonso Soto: Raul Escobar; Humberto Rodriguez; gathered during these visits as well as from other sources, Guillermo Cano; Dr. Peter Keller; Dr. James Shigley; this article reviews the fascinating history of mining at Benny Bazalel: Alberto Florez; and Cornelio Torres. Unless otherwise noted, allof the locality photos are Coscuez, describes thegeology of the area and the nature of by the author. mining operations, and examines the gemology of the Cos- 0 7986 Gemological Institute of America cuez emeralds.

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 67 HISTORY jungle traps, camouflaged pits, and numerous for- Much interesting history about the Spanish dis- tifications. covery and conquest of the emerald regions of Col- The Muzos inherited from their ancestors the ombia was published in 1948 by the Bank of the ancient legends surrounding the Fura-Tena, a co- Republic after it took over the administration of lossal pair of granite peaks (the tallest is 625 m emerald mining from the government. The author above the Minero River), approximately 40 km was G. Otero Mufioz, head of the Colombian Insti- from the Coscuez mine. As one approaches from tute of History. Unlike many other publications, the east, the Fura-Tena looms up majestically as a Esmeraldas de Colombia provided considerable sentinel to all who enter the emerald region. One information specifically on Coscuez. Much of Muzo legend states that Fura is the prince and what follows is from this source. Tena is the princess, both born to the god of the In their conquest of South America, beginning mountains. The god gave them wealth in the form in the 16th century, the Spaniards encountered of rich veins of emeralds, one of which was sacred Colombian emeralds among the local Indians as and not to be touched. A devil named Zarv con- far north as Mexico and as far south as Peru and vinced the princess to take the forbidden stones. northern Chile (Sinkankas, 1981). Judging from As she and the prince attempted to remove the the emeralds found in these ancient Indian sites, cursed emeralds, the god turned them into the two archaeologists believe that pre-Colombian tribes granite peaks, and their tears of remorse became began to systematically mine and trade emeralds the Minero River. as early as 1000 A.D. (Sinkankas, 1981). In the In 1538, Spanish Captain Luis Lanchero region near present-day Bogota, Spaniards led by launched the first campaign against the Muzo Gonzalo Jimenez de Quesada easily conquered the Indians (Piedrahita, 1881).Although Lanchero was Chibcha and Fusagasugae Indians. From the Chib- forced to retreat after much fighting, accounts of chas, the Spaniards learned of an emerald mine at a the campaign show that while butchering local place called Somondonco, which they located in wild turkeys for food, he and his soldiers found 1537 and later renamed Chivor (Wokittel, 1960). small emerald crystals in the craws. This was more The Chibchas also told them of another rich em- than enough incentive to convince the colonial erald area to the northwest. But to penetrate this governors to continue attempts to conquer that region, the Spaniards would first have to subdue a region. More campaigns were launched against the far more formidable tribe: the Muzos. The Muzos Muzos in 1545,1550, and 1551, but these too were were known as the most warlike, ferocious, and ultimately unsuccessful. valiant Indians in the region, and further were re- In 1558, however, Lanchero reentered Muzo ported to be cannibals. They were famous not only territory with a force consisting of Spanish soldiers for their poison arrows, but also for their hidden and members of local tribes that were also at war

68 Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 7COLOMBIA,

Figure 2. The Muzo and Chivor emerald-mining districts in Boyacd, Coloinbiu, Note the proximity of the Coscuez and Muzo mines to each other.

Mines %' Cities / *Rivers 0 20 km

with the Muzos. Up until this confrontation, the bringing the land of the Muzos under Spanish steel swords, armor, and firearms that had been control. adequate to conquer local Indian tribes throughout Following their success, in 1559 Lanchero's much of the continent had not been enough to men created a settlement close to where the subdue the Muzos. Their defeat was ultimately Indians' emerald mines were supposed to be and brought about by Lanchero1s timely use of a new called it Santisima Trinidad de 10s Muzos. Captain weapon: ferocious European hunting dogs. When Lanchero and his men soon located the mines and the dogs were turned loose in mid-battle, they cre- began to work them in the name of the Spanish ated havoc and confusion in the ranks of the Crown. Coscuez, named after an Indian princess, Indians (figure 3). In two costly and decisive bat- had been worked by the Indians for centuries prior tles, Lanchero and his forces finally succeeded in to the conquest and was undoubtedly one of the

Emeralds from Coscuez first located by the Spaniards. Ironically, a chest changed the operation at Muzo from tunneling to wound that Lanchero had received more than two open-cut mining, using a form of benching, that is, decades earlier in his first battle with the Muzos cutting the slopes horizontally in a step-like fash- had never healed, and in 1562 it turned gangrenous ion and washing away the resulting debris with and killed him. Yet the value of the legacy he left water. Because water was not as readily available, was evident in the eventual establishment of a Coscuez was worked less extensively at this time, royal counting house, a royal treasury, and numer- and mainly by tunneling. Paris is remembered ous cathedrals in the town of Muzo. The cost to the today primarily for his part in the discovery at Muzo Indians, however, was dear: Enslavement to Muzo of the mineral parisite, a rare fluorocarbo- work the mines and exposure to new diseases in- nate of cerium that was named in his honor. After troduced by the Spaniards killed thousands. Even- Paris, a number of foreign and Colombian lessees tually the loss of slave labor led to a steady decline continued to work the deposits with varying de- in emerald production, and the seat of local gov- grees of success. Little has been recorded about ernment was moved from Muzo to . activity at Coscuez during the latter half of the Spanish records indicate that in July of 1646 19th century except that it was repeatedly worked, there appeared in the city of Muzo a Captain abandoned, and reopened (Pogue, 1916, Op- Francisco de Ovalle, carrying a royal seal that penheim, 1948). named him Lord of Mines and overseer of all that he discovered in the Coscuez heights "as long as RECENT HISTORY AND the rocks there show the green of the emerald." PRODUCTION This situation caused some official confusion at The Muzo mine was responsible for most of the first, because the mine was already known and emeralds produced in the district from 1925 until being worked by others. In those days, however, it was closed again in 1938. In 1946, the Colom- the governorship changed hands frequently, and in bian government turned responsibility for the 1647 the new governor accepted the captain's mining and marketing of all emeralds over to the claim. This is one of the first instances on record Bank of the Republic. The bank was unable to where the Coscuez mine was considered sepa- maintain tight control, however, so illegal mining rately. Up until this time, in the history recorded and black marketing of emeralds flourished. Fi- by the Spaniards as well as in the government nally, in 1969, the government formed concessions and leases, the Coscuez mine was in- ECOMINAS (Empresa Colombiana de Minas- cluded with Muzo. Colombian Ministry of Mines) to control the During the colonial period, the miners ex- mines. In 1977, private companies were sought to tracted the emeralds simply by following the good work the mines on a five-year lease arrangement veins with tunnels. At Coscuez, a magnificent ("Coscuez, an Emerald Mine Reborn," 1979). The 18-oz. (550-ct) crystal was extracted by this Coscuez lease was awarded to ESMERACOL, a method, and was reportedly sent to a museum in company whose present major stockholders are Madrid. In the mid-1600s, a large cave-in at the Colombian Mines Co. (a Bogota-based cutter, bro- Coscuez mine buried almost 300 Spaniards and ker, and exporter), Victor Quintero (who also runs Indians. Work in the area was abandoned soon the Chivor mine), Jaime Murcia, and the family of after. Two centuries later, in 1850, mining opera- the late Juan Francisco (Pacho)Vargas. tions uncovered the same tunnel complete with Through ECOMINAS, the Colombian gov- the bones of the victims and their bamboo and ernment records the number of carats of emeralds metal tools (C. Torres, pers. comm., 1986). The legally exported each year. Until 1968, totals for vein became known to the miners as the Dead many of the individual mines were reported; since Man's Underpass, and today goes by the name El then, inexplicably, records show only totals ex- Espaiiol (The Spaniard). ported from all mines. In addition, illegal mining In 1824, the newly independent government of and unreported exporting diminish greatly the re- Colombia leased the mining area around Muzo to liability of the official statistics. It is not surpris- Colombian mineralogist Jose Ignacio Paris, who ing, then, that the author was unable to obtain any controlled the mining operations for the next 22 accurate, detailed production figures, either from years. During this period, acting on the advice of the government offices or from the mine officials. English mining engineer George Cheyne, Paris However, trends can be seen in the ECOMINAS

70 Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 Figure 3. Adorned with emeralds, the Muzo Indians fought the Spanish invaders fiercely. Ultimately, European hunting dogs were a deciding factor in Captain Luis Lanchero's defeat of the Muzos in 1558. From Otero Muiioz (1948). Reproduced by permission of the Colombian Institute of History.

records that substantiate the recent decline in pro- per year during the 1930s and 1950~~but that pro- duction from the Chivor mine, continued strong duction increased after 1963. Dealers in Bogota production from the Muzo mine, and significantly estimate that Muzo is currently producing several greater production from the Coscuez mine. For hundred thousand carats of emeralds annually. example, totals in the ECOMINAS production reg- Production at the Coscuez mine, unreported until istry show that the Chivor mine averaged 10,000- 1960, exceeded 25,000 ct in 1963, even surpassing 40,000 ct of gem-quality emeralds per year during Muzo for that year. Mr. Samuel Gad, a major part- the 1920s and 1930s, and 10,000-20,000 ct annu- ner in Colombian Mines Co., estimates that more ally until 1963, when production dropped and than 150,000 ct of emeralds per year are now being stayed low. Dealers in Bogota who are familiar mined at Coscuez (pers. comm., 1986). with the market reported to this author that in the 1960s and 1970s Chivor production was erratic- LOCATION AND ACCESS with some good and some bad years-but that it The Mountains begin in southern Chile and has stayed low since 1980. define the entire western edge of South America ECOMINAS records show that Muzo also av- until they reach Colombia in the north, where the eraged 10,000-40,000 ct of gem-quality emeralds chain divides into three prongs covering the west-

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 71 ern portion of the country. The world's richest scribed by several authors, including Pogue ( 1916), emerald-bearing region straddles the easternmost Schiebe (1933), Clements (19411, and Oppenheim prong, known as the Cordillera Oriental. The (1948). This work is summarized in Sinkankas Muzo district lies due north of Bogota, the capital (1981)and Keller (1981).In general, the district is of Colombia, in the northern part of this emerald- underlain by a great thickness of shales of early bearing zone. The Muzo and Coscuez mines lie Cretaceous age. These shales are intensely folded. within 10 km of each other in the state of Boyacd In addition, the area is transected by a number of (at 5O33'N, 740111Wand 5O39'N, 74O1 l1W, respec- northeast-trending faults that are accompanied by tively).Access to the mining region from Bogota is zones of brecciation. accomplished by helicopter, traveling approxi- Historical observations along with recent mately 105 km (70mi.) due north, or by field vehi- studies of these faults have shown that they are cle, traveling 260 km over what are primarily frequently concentrated at locations either of ex- winding paved and unpaved roads that descend istingemerald mines or areas of emerald minerali- from the high flat plain on which the capital city is zation. Thus, plans are under way to use fault situated to the mountainous subtropical terrain of patterns as promising exploration targets in future the lower altitudes. prospecting for emeralds in the Muzo district and The Muzo mine is about 800 m (2,625 ft.) in surrounding areas in this part of Colombia. On a above sea level and the Coscuez mine, 1120 m. In more local scale, experience has shown that areas both places, the land is fertile and the vegetation of emerald mineralization are indicated by certain thick. The weather at both mines is warm, al- changes in the color or texture of the host rock or though the heat at Muzo-which lies in a natural by areas of water seepage from the rocks which valley, sheltered from the wind-can be oppressive. may indicate the presence of a fault. In spite of their close proximity, Muzo and In the Muzo district, the geologic formation in Coscuez are not connected by any road. To get to which the emeralds are found is known as the Coscuez from Muzo by automobile, one has to go Villeta formation of Lower Cretaceous age 90 km east and then, just before Chiquinquird, (120- 130 million years old). This formation and take a second road northwest for approximately 90 other sedimentary rocks in the area are rich in km. A narrow footpath between the mines can be fossils, thus allowing for their age dating. The Vil- traversed in less than five hours. This path, as well leta formation consists of a great thickness of as the roads that lead to the mining areas, is used black, carbonaceous shales and minor amounts of only by the locals in that specific region. Territo- limestone. As with the other rocks in the district, riality is strong and has resulted in many local the rocks of the Villeta formation have been in- rivalries and skirmishes. Until conditions change, tensely folded, faulted, and fractured. The Villeta these areas should be visited only with extreme formation was divided into two members by Lleras caution and in the company of local residents. (1929).The underlying member consists of black carbonaceous shales and thinly bedded lime- stones. The overlying member is composed of GEOLOGY black to yellowish gray shales. Locally, these two The Coscuez mine (figure4) is one of several mines members are separated by two thin layers, which in the Muzo district, which also includes the Peria consist of calcite and minor quartz in a matrix of Blanca as well as the famous Muzo mine. The fine limestone cement; the difference between the mines in the district are located within roughly 30 two layers is principally textural. km of one another. Despite this close proximity, As at Muzo, the rocks of the Villeta formation there is no evidence that the mines are linked in at Coscuez are cut by numerous calcite veins that any way or that they are part of one continuous partly or completely fill fractures in the sediments. deposit. However, an understanding of the local The veins vary up to 35 cm in thickness and up to geology has been hampered by the dense vegeta- several meters or more in length. Having formed tion, rough topography, and limited detailed sci- along fractures in the host rock, the veins are ori- entific study of the entire area. Further investiga- ented in various directions within the rock but tions under way may reveal a more direct relation- often cut across the original bedding plane of the ship between the separate emerald deposits. sediments. The orientation of the veins can, how- The geology of the Muzo district has been de- ever, often be directly correlated with the local

72 Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 Figure 4. This view looking northeast at the Coscuez mine reveals both the ri~ssed-- topography of the region and the relatively small area of exploitation of the mine. Photo by Jack Rotlewicz.

pattern of fracturing in the rock. In some instances often discolored, with a yellowish gray appear- the veins intersect. The fractures are generally ance, in the area of the mineralized calcite veins. filled by the calcite vein material, but occasionally The emerald crystals usually occur attached to the there are open cavities within the calcite which wall of the fracture and are surrounded by calcite, may contain free-standing crystals. or they may be embedded within the calcite itself. For the most part, the emerald crystals are Field observations indicate that the best-quality found with the calcite along these fractures in the emeralds seem to be found in the narrower veins shale and limestone. The shale and limestone are (5- 10 cm thick]. Barriga Villalba (1948)hypothe-

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 73 Figure 5. Below Coscuez, the TUnel la Tabla penetrates 600 m into the mountain as the miners follow the emerald-bearing calcite veins. Note the plastic tubes Iused to deliver air into the tunnel. Until recently, tunneling was the principal method of mining at Coscuez. sized that this might be due to the mineralizing general agreement as to the basic features of this solutions and gasses entering the narrow fissures model of emerald formation, many questions with higher pressure, providing for better crystal- await answers from further geologic study. lization, but this has not been further evaluated. The crystals are randomly distributed, but locally MINING concentrated, within the calcite veins and can Historically, the rugged topography and steepness occur either singly or in groups. Associated with of the mountain on which the Coscuez mine is the emerald in the calcite veins are minerals such located have made access to Coscuez more diffi- as pyrite, quartz, dolomite, parisite, and (rarely) cult than Muzo (figure 4). In addition, the fluorite, apatite, albite, and barite. "Trapiche" em- emerald-bearing sedimentary rock at Coscuez is eralds, as well as both dolomite and pyrite, are somewhat harder than that found at Muzo. The more common at Muzo than they are at Coscuez. harder host rock, along with the fact that Coscuez Although the surface area of the Muzo mine is 10 does not have abundant water available, has made to 15 times larger than Coscuez, the latter has a open-cut mining difficult until relatively recently. greater concentration of emerald-bearing veins. Tunneling has been the chosen mining method The origin of the Coscuez, Muzo, and other throughout the history of Coscuez. One tunnel, emerald deposits in this region has long been the begun privately over 19 years ago, penetrates 600 subject of geologic study but as yet has not been m upward and into a mountain close to the main satisfactorily explained. Following their deposi- mine area (figure 5). The tunnel follows emerald- tion, the sedimentary rocks of the Muzo district bearing calcite veins and has produced enough in were subjected to a period of folding, faulting, and the past to keep a small group of locals occupied metamorphism. During these events, hydrother- working it today. As heavy machinery became mal solutions appear to have been derived from available in recent years, the more efficient open- within the sediments or from unidentified igneous cut mining became possible. Now the mine is sources. These solutions leached beryllium and worked with five bulldozers and some limited use other elements from the rocks occurring over a of dynamite (figure 6). As the potentially large area. Moving along zones of weakness in the emerald-bearing calcite veins are uncovered, they rocks, such as fault zones, the solutions deposited are checked by the miners with picks and then emerald and other minerals along fractures in the worked by hand if emeralds are found (figures 6 metamorphosed sediments. Although there is and 7).

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 Figure 6. Today, the mine owners at Coscuez use bulldozers to retrieve the emeralds more quickly and efficiently by the open-cut method. The bulldozers clear layers of black shale until the potentially emerald-bearing veins of white calcite are uncovered. On the right, a lone miner searches the white calcite for emeralds. Photo by lack Rotlewicz.

Figure 7. These Coscuez miners ~~-iepickstosearch for emeralds in the white calcite veins uncovered by the bulldozers. Figure 8. Independent guaqueros at Coscuez search for emeralds in the mine tailings that have been dumped into the small stream called La Culebrera. Whereas the Itoco River below Muzohas been known to support as many as 10,000 independent miners (see Keller, 1981), the author saw only 50 people working La Culebrera during his most recent visit.

The problem of the lack of abundant water at and at that point is called La Colombina, which Coscuez has lately been mitigated by the con- runs north into the Quebrada La Caca, which then struction of reservoirs fed by pumps at the upper feeds the Minero River. Many of the mining wastes levels of the mine. This water is released regularly are pushed by bulldozers into La Culebrera. Be- into various channels to help flush and move large cause the terrain at Coscuez is so steep, the mine amounts of mine tailings. Below the main mining tailings are much easier to remove here than at area, where the tailings settle, springs and small Muzo. streams feed a winding stream called La Culebrera All of the mines in Colombia share to differing (the Serpent Pit), referring either to the winding degrees the problem of numerous local guaqueros nature of the stream or to the rough reputation of ("diggers for treasure"), who live by selling what- the local independents who dig for emeralds in it. ever emeralds they can poach near or in the mines. La Culebrera widens after a few hundred meters In Muzo, guaqueros gather in the Itoco River. The

Emeralds from Coscucz GEMS & GEMOLOGY Summer 1986 tailings from the mine are washed by the river and tone, and clarity. Muzo emeralds tend to be a yield enough emeralds to support up to 10,000 well-saturated slightly yellowish green, while people. The mine owners stay within the mine and Chivor emeralds are generally less saturated and the guaqueros generally stay at the river. In Cos- more bluish green. Dealers in Bogota maintain cuez, however, there is no river, only La Culebrera. that the best crystals (in terms of clarity and "life") Although local miners report that the stream can come from Gachala. About Coscuez, though, these support more than 2,000 people, the author has same dealers have a saying: "From Coscuez comes seen only 50 or so (figure 8).It is more common in a little of every (Colombian) mine." There is no this area that the guaqueros enter the mine prop- one specific hue or degree of clarity associated erty at night and dig numerous tunnels in search of with Coscuez emeralds; rather, a variety of hues emeralds (figure 9).Territorial disputes among the occur, some of which are illustrated in figure 11. guaqueros make security and control a problem in Sometimes Coscuez crystals are lively, clean, and both Muzo and Coscuez, but with a stream that lightly saturated in color like those from GachalA, supports only a small number of people and a smal- sometimes the material is very bluish like Chivor, ler surface area to exploit, the job of securing Cos- and sometimes there is absolutely no difference cuez is more difficult. It is interesting to note that from Muzo color and quality. However, one type of the guaqueros of this region consist mainly of de- emerald commonly seen is typical only of Coscuez sccndants of the Muzo and Colima Indians. The (but by no means the only material). Using the reputations that the guaqueros at the different terminology of the GIA Colored Stone Grading mines have of aggressiveness and hostility tend to System, this type of Coscuez emerald can be de- correlate directly with how deeply into the terri- scribed as a strongly saturated, slightly bluish tory of the Muzo Indians the mine is found. Chivor and GachalA, which are outside of what was once Figure 9. The face of this hill at Coscuezisliterally the territoiiy of the Muzos, are relatively safe covered with tunnels that the local guaqueros mines and can even be visited by tourists. The have dug in the dark of night searching for Muzo mine, to the north, in Muzo territory, is emeralds. Photo by Jack Rotlewicz. considered dangerous for visitors, and Coscuez slightly more so. North of Coscuez, the Pefia Blanca mine is deepest in the heart of the Muzo Indians' old territory and correspondingly has by far the worst reputation of all the mines for danger and hostility among the locals. GEMOLOGY Crystallization. Observations by local miners have suggested that the Coscuez emerald can occur in more complex crystal forms than the Muzo emerald. While both mines produce many simple prismatic crystal forms, at Coscuez are found a large number of emeralds that are aggre- gates of three to six or more crystals all with indi- vidual terminations (figure 10).The faces tend to be brilliant with little or no etching. The crystals found at Muzo are generally shorter and less likely to have terminations and aggregates than at Cos- cuez. This phenomenon may have been caused by a lack of open space in the vein during crystalliza- tion, which could have inhibited crystal growth. Oppenheim (1948)speaks of the Coscuez emeralds as being "famous for their exceptional green color and elongated crystals." Color. In Colombia, the different mines are known to produce emeralds that differ slightly in color, Physical Properties. The properties of Coscuez emeralds do not vary significantly from those of Colombian emeralds in general: refractive index, 1.574- 1.580; birefringence, 0.006-0.007; specific gravity, 2.68-2.71; inert or slightly pink, orange, or red when exposed to long-wave ultraviolet radi- ation, and inert to short wave; pink to red when viewed with the emerald filter.

Inclusions. A preliminary examination with the microscope of approximately 50 faceted and rough emeralds from Muzo and Coscuez revealed no significant differences in the number or type of inclusions. Emeralds from both sources have two- and three-phase inclusions and the typical in- ternal features associated with Muzo-district ma- terial: "coaly" inclusions of carbonaceous matter, as well as calcite, albite, pyrite, quartz, and (rarely) barite, fluorite, and apatite. However, the main "jardin" feature of Coscuez and other Colombian emeralds is simply partially healed fractures. A seemingly endless variety of shapes and sizes of partially healed fractures and voids are found, which suggests interrupted and/or incomplete healing of fractures in the material. However, Muzo stones do seem to have more three-phase inclusions that are visible at lower magnifications (10x to 20 x) than other emeralds from Colombia, while the partially healed fractures in Coscuez emeralds seem to be slightly more unidirectional than Muzo stones. Figure 10. Note the multiple terminations on this 100+-ct emerald crystal from Coscuez. The highly saturated color evident here is also FUTURE POTENTIAL commonly seen in Coscuez emeralds. Specimen Because of the difficult terrain and the dense over- courtesy of AMGAD, Inc., New York; photo growth, systematic exploration of the Muzo and 0 Harold &> Erica Van Pelt. Chivor emerald districts has never taken place. In 1984, however, ECOMINAS geologists were able green stone with a medium dark to very dark tone. to define the boundaries of the potential emerald- Often the tone is so dark that transparency and bearing region into a polygon that reached from the "life" are diminished. These stones are still very Chivor-Guavio region to the Muzo-Coscuez re- attractive, especially to those who appreciate gion (again, see figure 2). Within those boundaries, strongly saturated color over brilliancy and trans- analyses of the fault patterns mentioned earlier in parency. Although the best color from Muzo is this article have revealed several high-probability better than the best from Coscuez, many Coscuez areas for emerald exploration; some are very close emeralds are among the finest that Colombia has to Muzo and Coscuez, and others are in areas that to offer. A top stone from Coscuez recently sold in have never before been explored (A. Florez, pers. New York for over US$25,000 per carat. comm., 1986). It should also be noted that Muzo-mine rough A cooperative technical survey and study is sometimes extremely color zoned, with a pale (1984-85)performed by United Nations scientists central core and darker, more saturated color on and Colombian geologists also showed promising the crystal's outer edges or "rind." Coscuez rough, results as well as some new geochemical guides for however, is generally uniform in color throughout emerald exploration. For regional prospecting, the the crystal. sodium content of stream sediments was recom-

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 mended as'a strong probable indicator of emerald- better understand the geology of this region and bearing deposits in nearby rock formations. identify new deposits. All current indicators are, Guided by the technical report, ECOMINAS geol- however, that the potential for continued strong ogists will begin prospecting in fall 1986 using the production of emeralds at Coscuez is good. amount of sodium, lithium, and lead found in the soils of various areas as a guide. Locally at Coscuez, the emerald-bearing sedi- REFERENCES ments are in many places 50 m thick and thus far Barriga Villalba A.M. (1948)Estudio cientifico. In Esmeraldas de Colombia, Banco de la Repilblica, Bogota, Colombia. exploitation has depleted very little of the imme- Beus A.A. (19701 Algunos rasgos geol6gicos de la region de diately workable deposits. Promising reserves are esmeralda Muzo-Coscuez. ECOMINAS, Bogota, Colombia. abundant, as is the optimism of ESMERACOL of- Clements T. 119411 The emerald mines of Muzo, Colombia. Gems a) Gemology, Vol. 3, No. 9, pp. 130-133. ficials (J. Rotlewicz, pers. comm., 1986). By con- Coscuez, an emerald mine reborn (1979).Colombian- trast, mining at Pefia Blanca ceased recently be- American Business, Vol. 16, p. 6. cause the emerald beds had been depleted in the Keller P. (1981)Emeraldsof Colombia. Gems e9 Gemology, Vol. 17, NO.2, pp. 80-92. main area and solid black shale bedrock encoun- Lleras C.R. (19291 Minas dc esmeraldas. Boletin de Minas y tered (A. Florez, pers. comm., 1986). Petroleos, Vol. 1, No. 1. Oppenheim V. (1948)The Muzo emerald zone, Colombia, South America. Economic Geology, Vol. 43, pp. 31-38. CONCLUSION Otero Mufioz G. (1948)Leyenda e historia. In Esmeraldas de Because Coscuez lies in the Muzo district, the Colombia, Banco de la Repiiblica, Bogota, Colombia. term Muzo emerald can apply to a Coscuez-mine Piedrahita L.F. de 1188 1 1 Historia Generaldelas Conquistas del Nuevo Reino de Granada. Bogotd, Colombia. stone. However, the Coscuez mine should be rec- Pogue J. (19161 The emerald deposits of Muzo, Colombia. ognized for what it is: one of the world's most Transactions of the American Institute of Mining and important emerald mines and worthy of consider- Metallurgical Engineers, Vol. 55, pp. 8 10-834. Schiebe R. (1933)Informe geol6gico sobre la mina de esmeral- ation on its own. das de Muzo. Compilaci6n de 10s Estudios Geol6gicos Although there are many similarities in the Oficiales en Colombia, Vol. 1, pp. 169- 198. historical development of the Muzo and Coscuez Sinkankas J. (19811 Emerald and Other Beryls. Chilton Book Co., Radnor, PA. mines and in the emeralds found there, there are Technical Report #I683 on Emerald Project (1984-5).United also differences in the geology of the two areas, the Nations, Washington, D.C., in cooperation with the Col- crystals produced, and the predominant color and ombian government. Wokittel R. (1960)Recursos minerales de Colombia. Compila- clarity of the stones mined. Studies are currently ci6n de 10s Estudios Geol6gicos Oficiales de Colombia, Vol. being conducted by the Colombian government to 10, pp. 341-352.

Emeralds from Coscuez GEMS & GEMOLOGY Summer 1986 79 THE ELAHERA GEM FIELD IN CENTRAL SRI LANKA By Mahinda Gz~nawardeneand Mahinda S. Rupasinghe

Commercially important quantities of he island of Sri Lanka, often referred to as the "jewel gem-quality sapphire, spinel, garnet, Tbox" of the Indian Ocean, has long been one of the chrysoberyl, zircon, tourmaline, and many major producers of fine-quality gemstones. Recent publi- other gemstones are being recovered from cations (e.g., Cooray, 1978; Munasinghe and Dissanayake, deep gem pits and surface excavations in 1981; Zwaan, 1982) have yielded general information on the Elahera gem field, a region incentral Sri gem occurrences in Sri Lanka but relatively little on spe- Lanka about 115 km northeast of the cific gem fields. Although the major gem locality in Sri capital city of Colombo, Large-scale mining is being conducted in this highly Lanka is still Ratnapura and its surroundings, Elahera, in metamorphosed sedimentary deposit by central Sri Lanka, has become the second largest gem field. the State Gem Corporation in collaboration Since the 1960s, Elahera has produced economic with the private sector. The chemistry and quantities of good to superior sapphire (figure l), spinel, gemological characteristics of these gem garnet, chrysoberyl, zircon, and tourmaline, as well as materials are discussed; in manyinstances, many other gem materials. Some of these stones are now in characteristic inclusions were identified by major museums or in the private collections of some of the microscopy, microprobe analysis, and X-ray world's wealthiest individuals. The poverty of those at the powder diffraction analysis. It is estimated pits and the glitter of those who reap the benefits have been that the Elahera gem field currently observed by the authors during the past few years and have provides approximately 35% of the led to the writing of this article on the history and geology gemstones exported from Sri Lanka. The continued steady production of good- of the Elahera region, as well as the gemology of the many quality gems is anticipated for fine materials found there. the future. HISTORY Recent archaeological discoveries have revealed that Ela- was an active gem center for many centuries. During the regime of King Parakramabahu, who ruled during the ABOUT THE AUTHORS 12th century A.D., even foreigners were allowed to mine in Mr. Gunawardene is president of the Lanka certain parts of the region. Recently, archaeologists exca- Foundation for the research of gemstones, and vated the remains of tools used to work the gem pits and director of MANYGEMS, a wholesale gem import firm in Hettenrodt, West . Dr. Rupasinghe even some engraved stones. However, civil wars and for- is a research associate at the Institute of eign invasions eventually forced the people to move to Fundamental Studies in Kandy, Sri Lanka. other areas of the country, leaving the troublesome king- Acknowledgments: The authors thank the officers of dom. The Elahera gem mines were gradually abandoned, the Gem Corporation of Sri Lanka for their many covered over by rice paddies. permission to photograph the Elahera gem field, and the many miners and villagers who recounted During the mid- 1940s) a Sri Lankan engineer working the history of the area. on an irrigation project along the Amban Ganga (ganga 01986 Gemological Institute of America means river) lost a ring along the side of the river

80 Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 1. Thegem corundums shown here illustrate some of the many colors found at the Elahera gem field, a major source of gem sapphires in the island nation of Sri Lanka. These stones average 1 ct. Photo 0 Tino Hammid.

while he was bathing. In the process of searching the functions of issuing gem-mining licenses and for the lost ring, he discovered a number of blue leasing government land for mining. In Elahera, and red pebbles, which proved to be either corun- the local farmers even used their own rice paddies dum or garnets. He soon started mining but kept for mining. In the late 1970s, the state body under- the discovery secret until early 1950. Around that took large-scale gem mining in collaboration with time, construction workers on the Elahera- the private sector. Current mining in the Elahera Pallegama road (see figure 2) found many pebbles area proceeds along the Elahera-Pallegama main of sapphire that had been exposed after a heavy road, particularly between the 19- and 24-mile rain. The news of their discovery gradually spread posts (figure 2), and is concentrated in the areas of among the professional gem miners in Ratnapura, Wallwala, Hattota-Amuna) Laggala, and Dahas- many of whom set up private, small-scale mining giriya. The State Gem Corporation has reported operations in the "new" district. that just one of the joint state/private industry Gem-mining activity in Sri Lanka escalated projects in this region-the Laggala-Pallegama after the government established the State Gem project-earned US$725,790 between June 30, Corporation in 1971. The corporation took over 1981 and April 13, 1985.

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 81 Figure 2. The Elahera gem field in central Sri Lanka is noted for its vast production of many gemstone varieties. The main gem mining activity is between the 19- and 24-mile posts.

LOCATION AND concentrated along the former main road (figure3). ACCESS The corporation, at its own expense, has built a The Elahera gem field covers approximately new road (marked in figure 2) to connect Elahera 150,000 m2 in the Matale and IJolonnaruwa dis- and Pallegama. The project area is closed to the tricts of central Sri Lanka. The map of the Elahera public, and anyone who wishes to visit the mines region in figure 2 extends from approximately must obtain a permit at the corporation's head 80°45to 80°55east and from 7O35' to 70501north. office in Colombo. The principal gem-mining area is centered at 80°50longitude from north to south. Two tribu- GEOLOGY taries of Sri Lanka's longest river, the Mahaweli The island of Sri Lanka is underlain almost en- Ganga, run through the main gem area. These are tirely by Precambrian metamorphic rocks which known as the Amban Ganga and the Kalu Ganga. have been subdivided by Cooray (1978)into three The lower course of the river system almost paral- groups: (1) Highland Group (pyroxene-granulite lels the main road between Elahera and Pallegama. facies), (2)Vijayan Complex (amphibole-granulite During the dry season, access to the gem mines facies), and (3) Southwestern Group (cordierite- is easily gained. During the rainy season (May to granulite facies). The Elahera region lies entirely September and late October through February), within the Highland Group terrain. The Highland however, the bridges are often under water. Group consists of hypersthene granites The State Gem Corporation has encouraged (charnockites), quartzites, marble (crystalline local farmers to continue their rice cultivation limestone), garnetiferous gneisses, hornblende without interruption. The area is attractive, with gneiss, granulites, and pegmatites (Dahanayake, green landscape and blue sky, and the mines are 1980).Gem mining is carried out in the residual.

82 Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 3. Large-scale gem mining is conducted along what was once the main bus route from Elahera to Pallegama, in the center of the Elahera gem field. Photo 1 by Marion Gunawardene. eluvial, and alluvial gravels overlying the High- The lithology and stratigraphy of the Elahera land Group metamorphics. According to area have been described in detail by Silva (1976), Dahanayake et al. (19801, the Elahera region is by Dahanayake (19801, and by Dahanayake et al. characterized by ridge and valley topography in a (1980).Munasinghe and Dissanayake (19811, Asadi plunging synclinal structure. This structure forms (1985),and Rupasinghe and Dissanayake (1986, in the wide valley and floodplain of the Kalu Ganga. press) have also reported on the origin of This floodplain is underlain by marble, while the gemstones in the island and are recommended for bordering,ridges consist of harder, more resistant further reading. garnetif&rous gneisses, charnockites, and The modes of occurrence of gem pits in Elahera quartzites. Granites do outcrop as elongated in- can be divided into two main types: residual and trusions along the length of the Kalu Ganga valley. alluvial. The residual gem pits contain large Where the granites have intruded and come into amounts of garnets, which are abundant in the contact with the marble, significant skarn de- gneisses. The gemstones found here are mostly posits, consisting of diopside, tremolite, scapolite, eroded and only rarely retain their distinct original spinel, and corundum, have developed. habits (figure 4).

Figure 4. A week's collection of rough blue and yellow sapphires found in Elahera are sorted here for faceting. Note the rounded appearance of the r crystals, probably the result of water transport. Stones courtesy of MANYGEMS, West Germany.

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 5. Two to threemeters below groundlevel, thegem-bearinggravelis extracted by workers. Natives use picks and shovels to excavate the gem gravel, a common practice in pit mines in the Elahera field.

The alluvial gem deposits are characterized by this method is economical. However, pit mining is clay and/or sand layers with abundant rock frag- disappearing now that the State Gem Corporation ments. The gem minerals can be widely distrib- has undertaken large-scale surface mining. The uted. They exhibit evidence of having traveled recovery methods currently in use include such over long distances and are often eroded. Most of modern techniques as scraping the overburden the gem pits essentially indicate the alluvial na- with bulldozers, which lowers the costs involved ture of deposits in the area, which in turn also and increases the yield of gem materials. With suggests that the various kinds of gemstones found both pit and surface mining, the gem-bearing in the deposits have different origins. gravel is first washed in cane baskets, sorted, and The Kalu Ganga has been a major vehicle for then dried in sunlight before it is again carefully transportation of the gem materials into the val- sorted by hand to recover any glittering pieces that ley, resulting in accumulations of deposits on hill were not identified during the washing. More than slopes as well as along the banks of the river. 650 miners currently work in the Elahera gem field. Unlike the early years of gem mining in this MINING METHODS region, when many of the operations were inde- Traditionally, mining commences with pendent, virtually all of the current miners are astrological consultations and a short religious employed by the State Gem Corporation and li- ritual offering foodstuff to "Bahirawaya," a spirit censed private enterprises. who is reported to be in charge of wealth hidden underneath the earth. THE GEMSTONES OF ELAHERA Because the soil in Elahera is relatively dry, Elahera produces a wide variety of gem materials, gem mining is less complicated than in wet zones including: blue, pink, yellow, violet, and like Ratnapura. Two methods are primarily used: "padparadschal' sapphires; marvelous color ranges pit mining (figure 5) and surface mining (figure 6). of spinel; rhodolite and hessonite garnets; The former is often carried out in rice paddies and chrysoberyls (includingalexandrite and chatoyant usually extends 3 to 10 m in depth. The gem- varieties); many colors of zircon; lovely green and bearing deposits are not far underground so "cognac" tourmalines; brownish green kor-

84 Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 6. These surface-mining areas measure 20 to 30 m2. The earth is first excavated by bulldozers to a level just above thegem-bearing gravel. The workers then carefully loosen thegemgravel with picks and remove it in cane baskets. Photo by Marion Gunawardene.

nerupines; near-colorless to yellowish or greenish blue (figure 1) and blue star (figure 7) sapphires. sinhalites; and many rare stones such as gem epi- The majority are of good to excellent quality, with dote, sillimanite (fibrolite], and taaffeite. Also even coloration and transparency. The best blue found in the locality are rock crystal quartz, ame- sapphires are comparable to the well-known thyst, and topaz, but for the most part these are Kashmir blues. The average-grade stones are more of mineralogic than gemological interest. lighter in color but still brilliant and internally Elahera is particularly noted as a source of large clean. The asteriated stones are usually grayish gem-quality corundums; crystals weighing as blue, but fine dark blue star sapphires are found on much as 200 ct have been recovered. occasion (again, see figure 7). More than 500 gem-quality sapphires, spinels, Corundum with a milky-white body color, garnets, chrysoberyls, tourmalines, kornerupines, called "geuda" sapphire, is commonly heat treated sinhalites, and rare gem taaffeites, epidotes, and to produce attractive blue stones (as discussed by sillimanites were examined during this study. The Nassau, 198 1; Gunaratne, 198 1; Hanni, 1982; stones ranged in size from 0.30 to 45.00 ct. The Gubelin, 1983; and Scarratt, 1983). Recently, a gemological properties of each gem material will large quantity of "geuda" sapphires from the Ela- be discussed below. Electron microprobe and neu- hera area surfaced on the local gem market. They tron activation analyses (NAA] were also con- appear to produce particularly nice blue stones ducted on samples obtained at various gem pits in with heat treatment. the Elahera area. Details of these chemical analy- The Elahera gem field also produces fine ses are available on request from the authors. yellow, pink, and violet sapphires (figure 1). The yellow stones vary in color from intense "golden Corundum. Elahera produces particularly fine yellow" (known as "golden sapphires" in the local

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 85 gem trade) to light or pale yellow (see, for example, the uncut yellows in figure 4).Often they contain a tinge of brown or rose; the latter tone is frequently misleadingly described as "padparadschat' (Crowningshield, 1983). Occasionally, good- quality "padparadschasl' are found in Elahera (fig- ure 8). Ruby is not common in Elahera, but the locality is noted for the particularly fine pink sap- phires found there. Violet sapphires from Elahera are often heat treated to remove the reddish hue and obtain a blue color (Gunaratne, 1981; Gunawardene, 1984). Color-change sapphires-blue in day or fluo- rescent light, purplish red in incandescent light- are occasionally encountered. The cause for the change of color has been detailed by Schmetzer et al. (1980).Corundum with color in only part of the crystal is also found in Elahera.

Chemical Analyses. Twenty different colors of co- rundum were selected from various gem pits in the Figure 8. This rare gem "padparadscha" sapphire (2.95 ct) is representative of some of the fine Elahera gem fields and subjected to quantitative stones of this unusual color found in Elahera. chemical (microprobe)analyses. They were found Stone courtesy of D, Humphrey; photo 0 Tino to have at least 99.43 wt.% A1203. The blue sap- Hammid. phires reveal an iron oxide content of 0.06 to 0.13 wt.% (as FeO) along with 0.02 to 0.05 wt.% Ti02. Light red to pink gem corundum contains 0.01 to similar colors from other localities (Schmetzer and 0.09 wt.% of Cr203,and the yellow sapphires show Bank, 1981; Schmetzer et al., 1983). 0.03 to 0.14 wt.% FeO. These concentrations are Optical Properties and Density. Refractive index, comparable to those determined for corundum of specific gravity, pleochroism, absorption spec- trum, and ultraviolet fluorescence were deter- mined for an assortment of colors of Elahera gem Figure 7. This 46.36-ct blue star sapphire found in corundum, as detailed in table 1. The observed Elahera indicates the availability of good refractive indices and birefringences remain rela- gemstones in the area. Stone courtesy of H. Roos. tively constant, revealing no distinguishing varia- tions either among the different colors or vis-a-vis corundum from other localities. Inclusions. The gem microscope revealed many solid and liquid inclusions that were subsequently identified by X-ray powder diffraction and mi- croprobe analyses. Abundant spinel crystals were common and proved to be the inclusion most characteristic of Elahera corundum (figure 9). Dark, platy, thin crystallites present were con- firmed to be phlogopite, biotite, graphite, and ilmenite. Rutile, as hair-fine needles, was also ob- served in many of the corundums. One Elahera sapphire contained an oriented rod-like rutile in- clusion (figure 10).As is common with other gems of Sri Lanka, the Elahera rubies and sapphires, par- ticularly the yellow sapphires, revealed abundant

86 Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 TABLE 1. Gemological properties of gem corundum, spinel, and garnet from the Elahera gem field.

Refractive Specific Absorptionc Reaction to LW/SW Gem materiala index Birefringence gravity Pleochroismb (in nm) U.V. radiation Inclusions

Corundum Blue (95) 1.760- 1.768 0.008 4.00 Greenish blue (M) 450 (d) Light blue (SW) Phlogopite, biotite, Dark inky blue 460 (wk) graphite, rutile, spinel, and zircon; healed "feathers," liquid "feathers," and negative crystals Yellow (22) 1.760-1.768 0.008 4.01 Orange-yellow (W) 694.2 (wk) Apricot reddish Spinel, zircon, and Grayish yellow 692.8 (wk) Apricot orange rutile; healed and liquid "feathers," negative crystals Ruby (2) and 1.761-1.769 0.008 3,99 Reddish violet 694.2 (d) Distinct reddish Rutile, apatite, pink (12) or pink (S) 692.8 (d) Distinct pink zircon, ilmenite, 668.0 (s) and graphite; 659.0 (w) fingerprint-like 476.5 (wk) liquid "feathers;" 475.0 (wk) negative crystals 468.5 (wk) Star sapphire 1,761-1.769 0.008 4.02 - Same as blue - Rutile and and ruby sapphire or ruby other crystal (16 total) inclusions mentioned above "Padparadscha" 1.760-1.768 0.008 4.00 Orange-yellow 694.2 (d) Strong apricot Rutile and (3) Yellowish orange 692.8 (d) various liquid "feat hers"

Spinel , % , Red, browni h 1.714-1.729 None 3.58-3.60 None 680.0 (d) Weak reddish Phlogopite mica red, pink (34' (mean 1.718) 675.0 (d) or no glow in typical; also spinel, 650.0 (d) brownish red apatite, and sphene Broad stones absorption covering 585 to 500 Blue, greenish 1.718-1.728 None 3.58-3.62 None 455.0 (s) None Same as above blue, violet (82) (mean 1.720) 470.0 (d) Green and bluish 1,716-1.753 None 3.60-4.05 None Same as above None Same as above green (3) Garnet Red (32) 1.749- 1.778 None 3.80-3.95 None 61 7.0 (w) None Rutile, apatite, and (mean 1.765) 576.0 (d) zircon; liquid 526.0 (d) ''feathers" 505.0 (d) Hessonite (20) 1.734- 1.738 None 3.58-3.64 None 547.0 (d) None Apatite crystals 490.0 (d) surrounded by 435.0 (d) swirl-like structural features aNumber of stones examined is g~venin parentheses. ^S =strong, M = medium, W - weak 'd = distinct, s = strong, w = weak, wk = very weak

zircon crystals with their typical healed fissures Spinel. Various colors of spinel are recovered in and altered structure resulting from exposure to this region of central Sri Lanka. The ratio of spinel radiation (Rupasinghe, 1984). Fingerprint-like to corundum is only 3:4 (see also, Munasinghe and liquid and/or healed "feathers" were common in Dissanayake, 1981). The predominant colors are most of the sapphires. Also detected were groups of blue, bluish green, greenish blue, purple, plum red, negative crystals, often in the form of feathers (fig- brownish red, lilac, and violet (figure 12). The ure 11). stones are often of good transparency. The star (6

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 87 Figure 9. Characteristic of the locality, spinel crystals commonly occur in Elahera corundum, Magnified OX, dark-field illumination,

Figure 10. Rutile formations such as this one in a rays) spinels are either dark brownish redl grayl or blue sapphire mined at Eluhera are occasionally black in body color and are usually opaque (Bank! encountered, Magnified 60x, dark-field 1980). Change-of-color spinels are found occa- illumination. sionally.

Chemical Analyses. To obtain detailed informa- seriesl or gahno-) spinels have a refractive tion on the chemistry of Elahera spinel! we sub- index range from 1.716 to 1.753. Specific jected 10 samples to both electron microprobe and gravity ranges from 3.60 to 4.05. neutron activation analysis (NAA). The major Visible-light absorption spectroscopy of red chemical componentsl A1203 and MgOl are in spinels from Elahera revealed a strong absorption normal proportions. The blue, green! and purplish line at 685.5 nm; no other absorption lines were red spinels investigated during this study contain seen in these stones. Iron played an important role iron (0.88 to 3.54 wt.% FeO) and extend into the in producing absorption bands at 45g1478! and 508 spinel-gahnite solid-solution series. This was fur- nm in bluel blue-green! greenish blue! and some ther confirmed by the amount of Zn present (350-750 ppm). The purplish red sample also con- tains 480 ppm of Cr. Anderson et al. (1937) and Anderson (19641 have detailed the properties of Figure 11. Negative crystal ii~clusionsarranged zinc spinels. somewhat like a feather within a blue sapphire from Elahera. Magnified 40x, transmitted Optical Properties and Density. The refractive illumination with color filters. indices and density values of Elahera gem spinels fall into three categories: 1. The redl brownish redl and pink spinels have a refractive index range from 1.714 to 1.729 with a mean value of 1.718. Specific gravity ranges from 3.58 to 3.60. 2. The blue! greenish bluel and violet spinels have a refractive index range from 1.718 to 1.728 with a mean value of 1.720. Specific gravity ranges from 3.58 to 3.62. 3. The green and bluish green (spinel-gahnite

88 Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 12. These gem spinels from Sri Lanlia (6 -55 ct) ill~zstratesome of the many colors found at the Elahera gem field. Stones courtesy of the Hixon Collection at the Los Angeles County Natural History Museum; photo 0 Harold ed Erica Van Pelt.

violet spinels. Much weaker absorption lines were (variety hessonite). The rhodolites, which are also visible at 635) 585) 555, 443, and 433 nm. more abundant than the hessonites, commonly are transparent and range in color from pink to pur- Znclusions. Guest minerals detected in Elahera plish red. The hessonites usually range from gem spinels include spinel (in feathery forma- orange-red to yellowish orange, although some tions], apatite, and sphene. Phlogopite (figure 13) samples resemble malaia garnet, a rich reddish seems to be typical of spinels found in central Sri orange. However, the majority of hessonites from Lanka. this locality tend to appear clo~idy,

Garnets. Gemologicallyl the garnets found in Chemical Analyses. Three purplish red garnets Elahera can be classified as rhodolite and grossular were analyzed by the microprobe. The Si02 con-

Gemstones of Elahera GEMS &GEMOLOGY Summer 1986 89 -- r- - Figure 14. Idiomorphic uputite und three- dimensionally oriented rutile in a rliodolite Figure 13. Phlogopite mica is a common inclusion garnet from Elahera. Magnified SOX,darl<-field in spinel found in central Sri Lanka, Magnified illumination. 35 x, darlz-field illuminution. Other Gem Materials. Twenty samples each of tent varied slightly from 40.02 to 41.48 wt.%, and chrysoberyll zirconl tourmalinel kornerupine) and A1203 varied from 22.87 to 23.09 wt.Yo, whereas sinhalite (seel for example! figure 15)! as well as 10 FeO and MgO contents were calculated as 18.14 to samples of rare gem taaffeitel epidote) and 15.82 wt.% and 13.93-15.01 wt.%, respectively. sinhalite from Elahera were also studied. The Less CaO (1.34-1.89 wt.%) and MnO (0.47-0.53 gemological properties for these stones are re- wt.'?~)were detected. On the basis of the data) ported in table 2. A number of the chry~oberyls~ these garnets can readily be classified as interme- zirconsl tourmalinesl kornerupine~~and sinhalites diate members of the pyrope-almandine solid- were also chemically analyzed by means of the solution series (Manson and Stocktonl 1981). microprobe andl in the case of zirconl by neutron activation analysis. Differences were noted in the Optical Properties and Density. Refractive index chemistry of the Elahera stones as compared to and specific gravity were determined for 32 that of similar material from other localitiesj the rhodolite and 20 hessonite garnets from Elahera. A results of these analyses are available from the refractive index range of 1.749-1.778) with a mean authors on request. Following are observations on value of 1.765) was recorded for the rhodolites. some of the more important gems within this These same stones varied in density from 3.80 to group, 3.95. The refractive indices of Elahera hessonite range from 1.734 to 1.738) with a density variation Chrysoberyl. Brown) brownish green) and greenish of 3.58 to 3.64. yellow chrysoberyls (figure 15) are common in The iron content in rhodolite garnets influ- Elahera. Cat's-eye stones are also found here. The ences their absorption spectruml which exhibits color-change variety! alexandrite) is seenl but only lines at 617! 57b1 526) 505! 476! 438) 428! and 404 rarely. nm. The spectrum of the hessonite (also iron- When examined with the microscopel the related) shows peaks at 547! 490, and 435 nm. Elahera chrysoberyls, including alexandrite and chatoyant stones, were found to be relatively clean Inclzzsions. Inclusions of rutile) apatite! and zircon and transparent. The most diagnostic features are seem to be common in the rhodolite garnets [figure growth zoning parallel to the crystallographic axes 14). The apatite crystals were idiomorphic or and liquid (monophase) inclusions. The growth euhedral. The internal appearance of the hessonite zoning can be observed best under crossed polar- garnets is characterized by apatite crystals and ized light (figure 16). The monophase inclusions swirl-like structural features. occur as either feathery or single-cavity forma-

Gemstonw of Elahera GEMS & GEMOLOGY Summer 1986 ------TABLE 2. Gemological properties of gem chrysoberyl, zircon, tourmaline, kornerupine, sinhalite, laaffeite, epidote, and sillimanite from the Elahera gem field.

Refractive Specific Absorption Reaction to U.V. radiation Gem materiala index Birefringence gravity (in nm)b Long wave Short wave Inclusions

Chrysoberyl Alexandrile (1) a = 1.745 0.01 0 3.70-3.72 680.5 (d) Weak Weak Growth zoning in p = 1.749 678.5 (d) reddish reddish various directions, y = 1.755 665.0 (w) liquid "feathers," 655.0 (w) and two-phase 649.0 (w) inclusions 640.0 to 560.0 (wd) 473.0 (wk) 468.0 (wk) Cat's-eye (5) a = 1.741 0.009-0.012 3.70-3.74 445,O (s) None None Fine parallel oriented -1.745 hollow tubes y = 1,750 -1.757 Other colors (10) a = 1.742 0.008-0.015 3.71 -3.73 504.0 (d) None None Growth zoning in p = 1.748 495.0 (w) various directions, y = 1.757 485.0 (w) fingerprint-like 445.0 (s) liquid "feathers," and Lwo-phase inclusions Zircon Intermediate = 1.838 0 006-0.008 4,04-4,06 653.5 (s) Weak to Weak to Disc-like fissures, tYPe (22) w = 1.830 Many absorp. distinct distinct zircon crystals, lines in the yellowish greenish various growth whole spectrum yellow phenomena and partly healed "fealhers" A general None None Zircon and apatite, absorption negative crystals, after 530.0 and healed liquid "feathers" Kornerupine (49) a = 1.668 0.01 2 3.33-3.36 503.0 (s) None None Apatite, zircon /3 = 1,679 446.0 (w) with circulating y = 1.680 430.0 (wk) cracks, two-phase ~nclusions,and liquid "feathers" Sinhalite (5) a = 1.669 0.036-0.037 3,48-3,49 525,O (w) None None Negative crystals /3 = 1 702 493.0 (d) and liquid "feather," y = 1.706 475.0 (d) two-phase inclusion 463.0 (d) 452.0 (d) 435.0 (d) Taaffeite (5) = 1.717 0.004-0.006 3.60-3.62 None None Well-formed apatite w = 1.723 crystals; spinel, phlogopite mica, and zircon; "fingerprints" of negative crystals Epidote (2) a = 1,732 0.035 3,44 457.0 (wk) None None "Feathers" and p = 1,746 455.0 (s) growth lines y = 1.767 parallel to the horizontal crystal axes 462.0 (d) None None Apatite and zircon 441 .O (d) with mica(?); 41 0.0 (wk) "feathers" of negative crystals and liquid droplets; growth tubes parallel to one crystallographic axis in chatoyant stones aNumber 01 s!ones examined is g~venin parentheses bd = dist~ncl,s = slrong, w = weak, wk = very weak

-- --

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 91 tions (figure 17).These inclusions are quite typical of Elahera alexandrite and can be used to distin- guish it both from synthetics and from natural alexandrite found elsewhere.

Zircon. The various colors found at Elahera are either low orl most commonly, intermediate types. Brown) green) yellow, reddish brownl and yellowish brown zircons (figure 18) are mined here. The chemistry and fluorescence behavior of zircon and its radioactive rare earth elements have been described in detail by Schwarz (1982) and Rupasinghe (1984).When viewed with the micro- scope) the Elahera zircons revealed many interest- ing internal features. Most abundant are the disc- like fissures that parallel one another. These discs are randomly oriented with respect to crys- tallographic directions. Also noted were euhedral zircon crystals and secondary growth zoning.

Tourmaline. Elahera is not well known for tour- maline) but greenish brown and dark green stones are occasionally found (again) see figure 18). The Elahera tourmalines exhibit a yellowish brown pleochroism that is attractive when the stones are faceted in the proper direction. They are often clean and of good transparency. When viewed with the microscopel tourmalines from Elahera exhibit a large number of zirconsl negative crystalsl pris- matic apatite crystals with two-phase inclusionsI Figure 15. This faceted light green chrysoberyl and various liquid and healed "feathers." (8.95 ct) and the accompanying 17.57-ct crystal are representative of some of the material fo~lnd Kornerupine. Gem-quality kornerupine is quite at the Elahera gem field. Photo 0 Tino Hammid. abundant in Elahera. The most common colors

Figure 16. Polysynthetjc twinning lamcllae in Fig~lre17. Typical forms of liquid "feathers" and nat~lralalexandrite from Elahera. Magnified25 x, cavities in gem alexandrite from central Sri crossed polarized light. Lanku. Magnified 28 x, transmitted illumination,

92 Gemstones of Elahera GEMS & GEMOLOGY Summa 1986 Figure 1.8. The color varieties shown here are typical of the following gems found at Elahera (clockwise, starting with the green stone a1 top): green zircon (4.43 ct), yellow zircon (2,78 ct), brownish green tourmaline (3.41 ct), reddish brown zircon (1.48 ct), green kornerupine (0.72 ct), dark green tourmaline (2.92 ct), and brownish yellow sinhalite (4.93 ct). Photo 0 Tino Hammid.

range from brownish green to greenish brown sinhalite (figure 18) with good transparency is also (again, see figure 18).Well-formed apatite and zir- often found in Elahera (Claringbull and Hey, 1952; con crystals surrounded by tension fissures are Henn, 1985).When viewed with the microscope, common inclusions in Elahera kornerupines. Ori- the gem sinhalites from this region frequently ap- ented two-phase inclusions were also seen in some pear clean. However, they occasionally exhibit a of the stones studied. network of negative crystals and needle-like in- clusions as described by Gunawardene and Sinhalite. Near-colorless to brownish yellow Gunawardene (1986).

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Figure 19. Export earnings by Sri Lanka for unset 50 - gemstones during the period 1947-1984, in U.S. dollars. Source: Sri Lanka Customs Department.

40 -

30 -

Millions of us $

20 -

10 -

CURRENT PRODUCTION AND annually in recent years. The flow of gemstones PROSPECTS FOR THE FUTURE from the Elahera district appears to be steady, so no In Sri Lanka, the Elahera gem field is now second significant fall-off in production is anticipated in only to Ratnapura in the production of gemstones the near future. suitable for jewelry. While total exports of loose gems from Sri Lanka have dropped significantly from their 1980 peak of more than $40 million annually, they appear to have stabilized at be- REFERENCES tween $15 million and $20 million in recent years Anderson B.W. (1964)Three stones for the record. Journal of Gemmology, Vol. 9, No. 7, pp. 215-221. (figure 19). Although specific production figures Anderson B.W., Payne C.J., Hey M.H. (1937) Magnesium-zinc- are as elusive for this locality as they are for most spinels from Ceylon. Mineralogical Magazine, Vol. 24, pp. others, the authors estimate that Elahera contrib- 547-554. Asadi B. (1985) Geochemische und pctrographische unter- utes 35% of these exports, or approximately suchungen an Edelstein-fuhrenden Gestein. Unpublished 15,000 kg of sapphires and 8,500 kg of other stones thesis, University of Mainz, West Germany.

Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 Bank H. (1980) Sternspinelle aus Sri Lanka. Zeitschrift der Manson D.V., Stockton C.M. (1981) Gem garnets in the red- Deutschen Gernmologischen Gesellschaft, Vol. 29, No. 1/2, to-violet color range. Gems a) Gemology, Vol. 17, No. 4, pp. pp. 94-95. 191 -204. Claringbull G.F., Hcy M.H. (1952) Sinhalite, a new mineral. Munasinghe T., Dissanayake C.B. (1981) The origin of Mineralogical Magazine, Vol. 29, pp. 84 1-849. gemstones of Sri Lanka. Economic Geology, Vol. 76, No. 5, Cooray P.G. (1978) Geology of Sri Lanka. In P. Nutaloya, ed., pp. 1216-1225. Regional Conference on Geology and Mineral Resources, Nassau K. (19811 Heat treating ruby and sapphire: technical Southeast , Vol. 3, Bangkok, pp. 701-710. aspects. Gems a) Gemology, Vol. 17, No. 2, pp. 121- 13 1. Crowningshield R. (1983) Pad~aradscha:What's in a name? Rupasinghe M.S. (1984) Radioactive gem minerals from Sri Gems ei) Gemology, Vol. 19, No. 1, pp. 30-36. Lanka. fournal of the Gemmologists Association of Sri Dahanayake K, (1980)Modes of occurrence and provenance of Lanka, Vol. 1,No. 1,pp.S-12. gemstones of Sri Lanka. Mineraliiim Deposits, Vol. 15, p. Rupasinghe M.S., Dissanayake C.B. (1986) Charnockites and 81. thegenesis of gem minerals of Sri Lanka. Chemical Geology Dahanayake K., Liyanage A.N., Ranasinghe A.P. (1980)Genesis (in press). of sedimentary gem deposits in Sri Lanka. Sedimentary Scarratt K. (1983)Heat treated sapphires. Retail Jeweler, Vol. Geology, Vol. 25, pp. 105-115. 22, No. 543, pp. 16 and 26. Gubelin E. (1983) Identification of the new synthetic and Schmetzer K., Bank H. (1981)The colour of natural corundum. treated sapphires.fournalof Geminology, Vol. 18, No. 8, pp. Neues fahrbuch fur Mineralogie Monaishefte, Vol. 2, pp. 677-706. 59-68, Gunaratne H.S. (19811 "Geuda sapphires1'-their colouring el- Schmetzer K., Bank H., Gubelin E. (1980)The alexandrite effect ements and their reaction to heat. Journal of Gemmology, in minerals: chrysoberyl, garnet, corundum, fluorite. Neues Vol. 17, No. 5, pp. 292-300. fahrbuch fir Mineralogie Abhandlungen, Vol. 138, pp. Gunawardene M. (19841 Contribution towards the identifica- 147-164. tion of treated corundums: heat and diffusion treated rubies. Schmetzer K., Bosshart G., Hanni H.A. (1983) Naturally- fournal of Gemmology, Vol. 17, No. 4, pp. 298-310. coloured and treated yellow and orange-brown sapphires. Gunawardene M., Gunawardene M. (19861 An unusual fournal of Gemmology, Vol. 18, pp. 607-622. needle-like inclusion in gem sinhalite from Elahera, Sri Schwarz D. (1982)Chemismus und Fluoreszenzverhalten von Lanka. Journal of Gemmology (in press]. Zirkon (ZrSi04).Ul~ren, Juwelen, Schmuck, Vols. 3 and 17, Hanni H.A. (1982)Characteristics of heat treated and diffusion pp. 21 7-220 and 237-240, respectively. treated corundums. fournal Suisse de Horlogerie et de Bi- Silva K.K.M.W. (1976)Some geological aspects of the Elahera jouterie, Vol. 5, 5 pp. gem field, Sri Lanka (abstract).Sri Lanka Association for the Hem U. (19d5)Untersuchungen an Kornerupine und Sinhalit Advancement of the Sciences, 32nd Annual Session. von Elahera, Sri Lanka. Zeitschrift der Deutschen Cem- Zwaan P. (1982)Sri Lanka: The gem island. Gems and Gemol- mologischen Gesellschaft, Vol. 34, No. 1/2, pp. 13-19. ogy, Vol. 18, No. 2, p. 62-71.

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Gemstones of Elahera GEMS & GEMOLOGY Summer 1986 NOTES AND NEW TECHNIQUES

SOME UNUSUAL SILLIMANITE CAT'S-EYES By E. Giibelin, M, Weibel, and C. P. Woensdregt

Brown-black sillimanite cat's-eyes from Sri Lanka thin-section study and the ion etching necessary present an unusually sharp band, which would make for subsequent electron diffraction. them extraordinary gems wereit not for therather un- This article summarizes the results of the elec- attractive body color of the stones. A study of six of tron microscope study of the inclusions causing these stones found that they contain 0.5 wt.% iron the chatoyancy, as well as the gemological charac- oxide. The principal inclusion mineral is ilmenite, teristics of this unusual material. which occurs in elongated, submicroscopically thin lamellae. Complex thicker lamellae consist of hercy- EXPERIMENTAL METHODS nite spinel grown together with a member of the pyroxene group. These thicker inclusions were not Chatoyancy, like asterism, is caused by the scat- foundin all of the specimens investigated. tering of light on numerous fibrous inclusions aligned in one or more directions in the host crys- tal; proper cutting en cabochon is required to re- veal the phenomenon. For good chatoyancy or asterism, the elongated inclusions must be thin sillimanite, also known as fibrolite, is a common compared to the wavelengths of light (Weibel, metamorphic mineral. Cuttable material is ex- 1985). Such minute crystal individuals are not ac- tremely rare but is found in the Mogok Stone Tract cessible to ordinary microscopy and X-ray analy- of Burma and in the Sri Lankan gem gravels, as sis. Even though the inclusions may show up in a transparent rounded crystals with a blue, violet- thin section viewed with a polarizing microscope, blue, or grayish green hue (Webster, 1983). Re- the images that appear are not real, but rather are cently, deep brown to blackish sillimanite produced by the scattering of light. cabochons with a sharp chatoyancy have appeared Two electron-microscopic techniques are on the market and are claimed to be from Sri particularly useful for the identification of ultra- Lanka. In transmitted light, these cat's-eyes show fine inclusions in gemstones: a characteristic violet tinge. 1. A scanning electron microscope (SEM) fitted The Geochemical Laboratory in cooperation with an energy-dispersive X-ray microanalyzer with the Solid State Physics Laboratory (Swiss Federal Institute of Technology, Zurich, Switzer- land) has undertaken an electron-microscopic study of the new sillimanite cat's-eyes and the ABOUT THE AUTHORS oriented inclusions that cause their chatoyancy, Dr. Gobelin, a prominent gemologist and author, is from with R. Wessicken as analyst. For this study, six Meggen, Switzerland; Dr. Weibel is professor of geochemistry at sillimanite cat's-eyes, all purportedly from Sri the Swiss Federal Institute of Technology,Zurich, Switzerland, and has just publisheda new book on gemstones; andDr. Lanka, were acquired. They ranged in size up to Woensdregt is senior lecturer in crystallography at the Institute of 10 ct. The largest cabochon (figure 1)was cut paral- Earth Sciences, State University of Utrecht, the Netherlands. lel to the base and the lower half sacrificed to 0 7986 Gemological Institute of America

96 Notes and New Techniques GEMS & GEMOLOGY Summer 1986 tion patterns makes use of X-ray crystallography, which can distinguish the inclusion from the host. The details of the procedure followed and the in- tergrowth relations between the host and the in- clusion will be published in a forthcoming paper intended for a crystallographic journal.

CHEMISTRY AND STRUCTURE The largest sillimanite cat's-eye was analyzed for iron with the SEM. Between 0.5 and 0.6 wt.% FeiOi was found in the matrix. Since the chemical formula for sillimanite is A12SiOs, trivalent iron presumably substitutes for aluminum. Elongated lamellar inclusions are aligned strictly parallel to the c-axis of the sillimanite, which has a very per- fect cleavage parallel to the c- and a-axes, that is the crystal plane (010).The cutter of a sillimanite cat's-eye usually chooses the cleavage plane of the Figure 1. One of the sillimanite cat's-eyes from Sri Lanka that was studied by the authors. The stone to coincide with the base of the cabochon, relatively flat cabochon measures 13 mmand but any orientation of the cabochon base parallel weighs 5.24 ct (although the stone originally to the c-axis of the sillimanite would produce an weighed 10 ct, the base was cut off for the analy- optimum light bind over the center of the stone. ses). ~ote'fhebifurcated light bandproduced by irregularit/@in the orientation of the fibrous in- GEMOLOGICAL PROPERTIES clusions. The common optical properties of these silliman- ite cat's-eyes concur very well with those of other sillimanites from Sri Lanka. The determinations enables the surface of a polished stone to be were made by standard gemological procedures, viewed and a chemical analysis to be made of and the following properties were found: areas as small as 1 pm. 2. A transmission electron microscope combined Refractive indices: a = 1.660, /3 = 1.662, y = with an energy-dispersive X-ray microanalyzer 1.680 serves as a high-resolution analyzer down to Birefringence: + 0.020, 2V = 30Â about 300 nm. The transmission electron Pleochroism: a = pale yellow, /3 = clove- microscope produces not only an image, but brown, y = gray-brown also a diffraction pattern, of the crystal lattice of Absorption: very faint shadows at 410, 441, an ultrafine inclusion. A thin slice of the gem- and 462 nm stone must be etched by ion-beam thinning to Density: 3.257 g/cm3 (average of four hydro- reduce its thickness to less than 100 nm. Thus, static measurements) a chip of the gemstone under consideration must be sacrificed for the analysis (Wenk, ORIENTED INCLUSIONS 1976). If a thin section of a sillimanite cat's-eye is viewed For this study, both these techniques were ap- through an ordinary light microscope, most of the plied. With the SEM alone (method l),the oriented oriented fibers show up as scattering images (fig- inclusions in the sillimanite cat's-eye could not be ure 2), since they are thinner than the wavelengths identified with certainty but required a more ex- of visible light (Weibel, 1985).In a more sophisti- tensive investigation drawing on electron diffrac- cated study with the electron microscope, we tion (method 2). The reason is that the matrix found two varieties of fibrous inclusions, both of around a very small inclusion also tends to be which measure up to a millimeter in length. First, excited by the electron beam, so the spectrogram there are relatively thick crystal lamellae (fig- obtained is a mixture of the compositions of the ure 3), which have a rectangular cross-section of 1 inclusion and the matrix. The analysis of diffrac- to 10 pm and consist of intergrowths of hercynite

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 Figure 3. A scanning electron micrograph taken from a cleavage plane of a sillimanite cat's-eye. As in the photomicrograph shown in figure 2, the lamellae seen here are intergrowths of a pyroxene and hercynite spinel. The much thinnei ilmenite lamellae are not resolved.

spinel and probably a pyroxene. The spinel was CONCLUSION identified by energy-dispersive X-ray microanal- The characterization of a cat's-eye mineral re- ysis and electron diffraction, whereas the nature of quires the exact identification of the inclusions the pyroxene has not yet been established. that cause the optical phenomenon. Moreover, the Since these thicker fibers do not occur in all of study of cat's-eyes reveals intriguing insights into the sillimanite cat's-eyes included in our investi- the intergrowth of mineral phases, some of which gation, the chatoyancy must be caused by a second appear to develop asymmetrically under strain. type of elongated structure. Electron diffraction Thus, even a cubic crystal may display extreme showed that a more essential quantity of needles is elongation. composed of the mineral ilmenite. The ilmenite Apart from this, both chatoyancy and asterism occurs as thinner lamellae, 0.05 to 0.5 km across, (which can be described as double or triple chatoy- with a rectangular cross-section that is probably ancy) give a cabochon-cut stone an individual ap- imposed by the sillimanite structure. It is a most peal highly appreciated by professional as well as striking fact that in both systems of needles, the amateur gemologists and gem collectors. An emi- elongation contravenes the common crystal habit nent scientific and aesthetic value is inherent in expected from the crystal structure of the included this strange group of rare gems. mineral. Ilmenite as oriented inclusions is responsible not only for the chatoyancy and blackish appear- REFERENCES ance of the sillimanite cat's-eyes, but also for the Webster R. (1983) Gems, Their Sources, Descriptions and chatoyancy of some rare aquamarine and chryso- Identification, 4th ed. Revised by B.W. Anderson, beryl cat's-eyes (unpublished analyses of the au- Butterworths, London. thors).Most chrysoberyl cat's-eye, however, owes Weibel M. (19851Edelsteine undihre Mineraleinscl~ltisse.ASC Verlag, Zflrich. its chatoyancy to oriented rutile silk (unpublished Wenk H.-R. (1976) Electron Microscopy in Mineralogy. analyses of the authors). Springer-Verlag, New York.

98 Notes and New Techniques GEMS & GEMOLOGY Summer 1986 AN EXAMINATION OF FOUR IMPORTANT GEMS By C. W.Fryer and John I. Koivula

The authors report on their gemological examinations of four important gemstones: the Star of Bombay sap- phire, the Portuguese diamond, and two large dia- monds known as the Marie Antoinette earrings, all of which are part of the collection at the Smithsonian Institution. Brief historical information on some of the pieces is also included.

In May of 1985, the Los Angeles County Museum of Natural History opened a new gallery devoted to Gemstones and Their Origins. This gallery, funded by Mr. Alex Deutsch and the Weingart Founda- tion, is a permanent part of the E. Hadley Stuart, Jr., Hall of Gems and Minerals. In conjunction with the opening of the new gallery, arrangements were ma,de for a special exhibit of fine jewelry items provided by Harry Winston, Inc. of New York as well as some important stones from the co11ectionof theU.S. National Museum of Natural Figure 1. The 182-ct Star of Bombay sapphire. History in Washington, D.C, a part of the Smith- Courtesy of the Smithsonian Institution. sonian Institution. While the special exhibit was in '0s Angeles, the authors were offered the rare absorption in the green area of the spectrum, opportunity to perform gemological examinations No evidence of any lines at 460.0 nm or 470.0 nm on three famous pieces from the Smithsonian col- was observed. The stone is inert to ultraviolet lection: the Star of Bombay sapphire, the Portu- irradiation. guese diamond, and the Marie Antoinette earrings. Several interesting inclusions were observed The results of these examinations are reported with the microscope, In addition to the rutile nee- below. dies responsible for the star, the most prominent inclusion found in the Star of Bombay is a primary THE STAR OF BOMBAY SAPPHIRE negative crystal that contains two different solid A bequest to the Smithsonian by movie phases (figure2) One phase is a small grouping of Mary Pickfordl the Star of is a medium- opaque dark gray to black submetallic hexagonal intensity blue oval star sapphire (figure 1) that measures 36.30 x 28.82 mmand is 17.55 mkdeep. Unfortunately, nothing is known of the history of ABOUT THE AUTHORS this stone before Miss Pickford obtained it. Using Mr. Fryer is chief gemologist, and Mr, Koivula is senior the weight gemologist, in the Research Department of the Gemological we estimated the weight to be approximately 184 Institute of America, Santa Monica, California. ct, in very close agreement withthe weight of 182 Acknowledgments: The authors would like to thank Dr. Peter ct recorded at the Smithsonian. The dichroic Keller for arranging the loan of these items with John Sampson White of the Smithsonian Institution. Our thanks also go to Dr. are distinct to and blu- Anfhony Kampf for inviting us to examine the stones andallowing ish green. The refractive index (spot method) is us to use the facilities of the Los Angeles County Museum of approximately 1.76- 1.77. The specific gravity Natural History. was not determined. Spectroscopic examination Figures 1,2, and 3 were photographed by the authors. revealed a sharp line at 450.0 nm and a general 01986 Gemological Institute of America

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 platelets which, from past experimentation with troy (156 ct). He stated that the stone had been similar solid phases in Sri Lankan sapphires, the found in Brazil, which was then a colony of Por- authors believe to be graphite. The second phase is tugal. Edwin Streeter (1882) also maintains that an unidentified stalk-like spray of birefringent the Regent of Portugal came from Brazil and states crystals extending inward from the cavity walls. that it was found by a slave near the Abaite River. Because primary negative crystals in Sri Lankan However, he lists the weight as 215 ct, which is corundums commonly contain carbon dioxide, we substantially larger than that given by Mawe. In thought that if the cabochon were slightly cooled any event, the stone was subsequently recut to its we might be able to observe a phase change present size and shape. Somewhere along the line (gas - liquid). After the stone was cooled by its name was shortened to the Portuguese. Accord- immersion in cold tap water, we did observe both ing to Krashes (1984), Harry Winston, Inc. pur- liquid and gaseous carbon dioxide in the cavity. chased the stone in 1951, sold it, bought it back, Slight warming with the microscope lamp caused and ultimately sold it to the Smithsonian in 1963. the two phases of carbon dioxide to homogenize The Portuguese is a lovely stone with a nearly and the meniscus between the liquid and gas bub- octagonal outline, the corners being almost the ble to disappear. These test results indicate that same length as the sides and ends. The diamond the stone is from Sri Lanka. measures 32.75 x 29.65 mm and is 16.01 mm deep. This conclusion was further supported by the It is set in a very simple four-prong mounting that presence of a slightly rounded, nearly equidimen- ensures that the stone will rest in an upright posi- sional, metallic opaque crystal that was visible tion when exhibited. The mounted stone could not without magnification. Although the inclusion be weighed, but the GIA weight estimation for- could not be analyzed because of its position mula indicated a weight of approximately 128 ct, within the stone, experiments on Sri Lankan sap- less than 1 ct difference from the recorded weight phires with very similar inclusions suggest that it of 127.01 ct (Krashes, 1984). is probably a protogenetic crystal of the iron sul- Although mounted stones cannot be graded fide pyrrhotite (figure 3). accurately for color, the authors tentatively as- signed a grade range of G to HI or I, on the GIA color THE PORTUGUESE DIAMOND scale, which is consistent with the observed pres- The Portuguese diamond (figure 4) was first men- ence of a 415.5-nm absorption line in the spec- tioned in the literature by John Mawe (18131, who trum. (Colorless stones [D on the GIA scale] do not referred to it as the Regent of Portugal and listed it show the 415.5-nm line.) No other absorption lines as the third largest known diamond, weighing 1 oz. were observed.

Figure 2. This negative crystal in the Star of Figure 3. This solid crystal inclusion in the Star of Bombay sapphire has two distinct solid crystal Bombay sapphire is probably pyrrhotite, a phases. Transmitted and oblique fiber-optic familiar inclusion in Sri Lankan corundum. illumination, magnified 15 X,

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 Figure 4. The 127.01-ct Portuguese diamond. Courtesy of the Smithsonian Institution; photo by S. Gipson, courtesy of the Los Angeles County Museum of Natural History.

8.

. I. Whatever color is present in the stone is most indication of any localized stress such as is usually assuredlySmaskedby the very strong blue fluores- found around inclusions. cence; in fact, the Portuguese was once thought to have been a blue diamond (Krashes, 1984). The THE MARIE ANTOINETTE EARRINGS stone fluoresces extremely strong blue on expo- Although the Marie Antoinette necklace is men- sure to either short- or long-wave ultraviolet radi- tioned several times in the literature, little has ation. Even the relatively low proportion of ultra- been recorded about the earrings (figure 5). They violet light in an incandescent light source will were probably part of a suite of extremely large cause the stone to fluoresce a soft blue color. In pear-shaped diamonds that were assembled by the addition, there is a decided blue color to the strong court jeweler for Madam Jeanne du Barry, mistress ray of light that is transmitted through the stone to Louis XV of . After his father's death, when it is placed over the diaphragm of a spectro- Louis XVI reportedly gave them to his queen, scope unit with the light turned on for spectro- Marie Antoinette, who is said to have worn them scopic observation. constantly. The earrings were left in the Tuileries The only reference to the clarity of the Portu- when the royal family attempted to escape from guese diamond that could be found in the litera- Paris in June, 1791. ture was that by Gaal (1977), who said that the The center stones in the earrings were the only stone was flawless. However, our examination of ones examined by the authors in detail. Although the mounted stone revealed a small bruise on the the stones are rather large pear shapes, they are junction between the first and second facets up very shallow. One measures 23.21 x 19.36mm and from the girdle on one side of the crown, and two is 6.80 mm deep, and the other measures 24.40 x very minor scratches on the table, which would 17.00 mm and is 5.13 mm deep. Application of the place it in the VVS category. These characteristics GIA weight estimation formula provided weights could have occurred subsequent to Gaal's report. of approximately 19 and 13 ct, respectively. It ap- However, there are also five extra facets at the pears that the weight of 36 ct each indicated on the corners of the pavilion facet junctions. The stone information card that accompanied the exhibit is was also examined with the polariscope, but only a in error and represents, instead, the total weight of generalized strain pattern was observed, with no the two stones.

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 101 Figure 5. The Marie Antoinette earrings. The large diamond drops weigh approximately 19 and 13 ct each, respectively. Courtesy of the Smithsonian Institution; photo 0 Harold s) Erica Van Pelt.

The stones appear to be colorless, or nearly so, CONCLUSION as would seem to be confirmed by the absence of a Few stones equal the Star of Bombay sapphire, 415.5-nm line in their absorption spectra. How- Portuguese diamond, and Marie Antoinette ear- ever, it should be noted that the stones were tested rings in size, quality and, in the case of the latter, at room temperature, and there is always the pos- historical interest. We hope that our examinations sibility of a weak 415.5 line becoming discernible will provide a more complete record on these if the stones were cryogenically cooled. One of the stones for future researchers, and that the oppor- stones was inert to any ultraviolet radiation, while tunity will become available to provide similar the other fluoresced a weak blue to both long- and reports on other named pieces as we seek to learn short-wave rays. more about these touchstones of gemology. Both stones had extremely thin girdles. As a result, over the years they have acquired a number of chips along the girdle edges. Some of these chips are relatively large and would probably place the REFERENCES stones in the VS category. Using a microscope at Gaal R.A.P. (1977) The Diamond Dictionary, 2nd ed. Gemolog- lox magnification, we did not see any internal ical Institute of America, Santa Monica, CA. characteristics other than bearding at the girdle Krashes L. (1984)Harry Winston: The Ultimate Jeweler. Harry edge. However, the stones would have to be graded Winston, Inc., New York, NY, and Gemological Institute of America, Santa Monica, CA. out of their mountings before any claims could be Mawe J. (18131A Treatise on Diamonds and Precious Stones. made that they might be potentially flawless if Longman, Hurst, Rees, Orme, and Brown, London, recut. Both stones showed considerable strain . Streeter E.W. (1882)The Great Diamonds of the World. Their when examined in the polariscope, but no local- History and Romance, 2nd ed. George Bell and Sons, Lon- ized strain pattern. don, England.

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 GREEN GLASS MADE OF MOUNT SAINT HELENS ASH? By Kurt Nassau

A specimen of green glass said tobe madefrom ash from glass in gemology, see Webster (1983)and Nassau the May 1980 eruption of Mount Saint Helen in (1980). Washington State was examined and compared with a black glass made by melting a sample of the ash. The glasses are quite different in their properties, and TESTING analytical results show that the green glass contains at A sample of Mount Saint Helens ash was heated in most 5%to 10% of mount Saint Helens ash, if any. a 3.75-cm (1.5-in.)alumina crucible in air in an electric furnace. Viscous flow began at about 1300°Cbut because of the high viscosity the air bubbles did not disappear until the ash had been heated for several hours at 1500°CThe result is On May 18, 1980, Mount Saint Helens, in an essentially black glass (figure 1, right), which Washington State, erupted violently. The result- appears dark gray-green when examined in thin ing ash cloud rose as high as 10 km (6mi.) into the splinters. The color is presumably derived from upper atmosphere, depositing some three cubic ligand field and charge transfer processes (Nassau, kilometers of material over several states. (About 1983)involving the high Fe and Ti content, and can 600,000 tons of ash-basically fine particles of be expected to vary somewhat depending on wheth- rock-fell on the town of Yakima, Washington, er the material is heated in an oxidizing or a reduc- alone.) The'author subsequently obtained samples ing environment. of ash from Yakima, Spokane, and other localities, The refractive index of the green glass is 1.508, including a large sample collected in central while the black glass showed considerable varia- Washington by C. B. Keenan. tion (1.500- 1.526), because the high viscosity The ash was determined to consist partly of inhibited mixing of the various components. Spe- glass and partly of crystalline material, including cific gravity (measured by the hydrostatic tech- quartz, feldspar, and other minerals. The particles nique) for the green sample was 2.448 and for the range from over 1 mm to less than 1 pm in size, and black, 2.485. The results for the two samples were have a bulk density of approximately 1.5 g/cm3 sufficiently different to throw doubt on the (Nassau, 1981). Chemical analysis of a variety of claimed origin of the green glass, even though ash samples revealed the following composition as some variability in the composition of the ash typical of this material: 64 wt.% Si02, 17 wt.% could be expected. A1203, 5 wt.% CaO, 4 wt.% FeO (total Fe), 4 wt.% Semiquantitative (relative)elemental analyses Na20, 2 wt.% K20, 2 wt.% MgO, and 1 wt.% Ti02 were performed by energy-dispersive X-ray fluo- (Nassau, 1981).In view of the high silicon, alumi- rescence using tungsten and chromium radiation num, and calcium contents, a glass made from this excitation. Some elements occur at similar con- ash would have very high melting and flow temper- centrations in both glasses: silicon is 20%, and atures and viscosity (McLellan and Shand, 1984). potassium 30%, higher in the green glass, while In 1983, a green glass appeared on the gem traces of chlorine, manganese, and zinc occur at market, mostly in the western United States, with about the same concentration in both glasses. the claim that it had been made by melting Mount Saint Helens ash; purchasers thus could assume that ash is the major ingredient. This seemed to be ABOUT THE AUTHOR a claim worth examining in view of the high melt- Dr. Nassau is a research scientist residing in Bernardsville, New ing point and viscosity expected of such a product. Jersey. An examination was undertaken when a sample, Acknowledgments: The author thanks Roger J. Cormier for providing a specimen of the green glass, and Christopher 13. shown in figure 1 (left),became available recently Keenan for supplying a large sample of Mount Saint Helens ash. from R. J. Cormier. For general discussions of glass, The photographs are by the author. see McLellan and Shand (1984);for discussions of 07986 Gemological Institute of America

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 103 Figure 1. Green glass (30 mm long) claimed to bemade from Mount Saint Helens ash, and black glass that the author made from a sample of ash.

Some elements are present at significantly higher concentrations in the green glass: approximately twice as much calcium, chromium, and zirconi- um, and three times as much copper, were pres- ent. Other elements have significantly higher con- centrations in the black glass: 25 times as much iron, 14 times as much titanium, and twice as much aluminum and strontium. These are all the elements that were detected; with the instrumen- tation used it is not possible to detect light ele- ments such as boron, sodium, and magnesium. Here again, a different origin is indicated for Figure 2. Left, the small, irregular pieces of green and black glass shown in figure 1 after heating to the two glasses. The high iron and titanium con- 800°Cright, the black glass heated to 1300°C tents in Mount Saint Helens ash (about 4 and 1 wt.% as oxides, respectively) are adequate to ac- ing point of the black glass is so high that it would count fully for the color in the black glass. Given be very difficult and costly to fabricate a uniform the lower amounts of these two elements (1/25 glass from it on a commercial scale. iron and 1/14 titanium) in, and the lighter color of, the green glass, one can deduce that the material CONCLUSION contains little if any Mount Saint Helens ash. Al- Green glass claimed to be made from ash from the lowing for the variability in composition of the ash 1980 eruption of Mount Saint Helens has signifi- and for the semiquantitative nature of the analy- cantly different properties and composition from sis, a maximum of 5% to 10% ash in the green glass actually made entirely from the ash. It con- glass is indicated. tains at most 5% to 10% of this ash, if any. One final and quite conclusive test was per- formed by placing small pieces of each glass on platinum foil and heating them in a furnace in air, REFERENCES increasing the temperature by 100° every 15 min- McLellan C. W,, Shand C. B. (1984)Glass Engineering Hand- utes. The green glass flowed at 800°Cthe black book, 3rd ed. McGraw-Hill, New York. glass did not flow until 1300° (figure 2). This Nassau K. (19801 Gems Made by Man. Chilton, Radnor, PA. Nassau K.(1981) Plates, quakes, volcanoes, and Mt. St. Helens - huge difference is undoubtedly caused by the Part IV: Mount Saint Helens. Lapidary Journal, Vol. 35, higher silicon and aluminum concentrations in NO. 8, pp. 1611-1624. the black glass and the probable presence of signif- Nassau K. (19831 The Physics and Chemistry of Color. Wiley and Sons, New York. icantly larger amounts of the undetermined oxides Webster R. (1983) Gems, 4th ed. Revised by B. W. Anderson of boron and sodium in the green glass. The melt- Butterworths, London.

Notes and New Techniques GEMS & GEMOLOGY Summer 1986 Editorial Forum

THE NEED TO KNOW: manuscripts were lost or destroyed, especially during ANOTHER EMERALD FAKE Diocletian's repression of Egypt (296 A.D.], the infor- mation was passed on through a combination of verbal We had no sooner received the Winter '85 edition of and written communications. It was not until the mid- Gems a) Gemology with your editorial on fakes, when 19th century that such practices came into disrepute. In in walked a man with three rough "emeralds" weighing 1858, Barbot wrote that, regarding the feeding of pearls 52,33, and 20 g, respectively. They came (wewere told] to chickens, he was inclined to believe that "this prac- from a "respected supplier" who had in turn obtained tice should be considered an old wives' tale." them from a mine in the Chitanti district of Zambia. The use of an acid to remove the external layer of a The crystals were in our possession for such a short pearl is also an old method, passed on in later years in while that no testing was possible. On eye examination, recipes published by Anselmus Boetius de Boot (1609) however, the "emeralds" appeared to be encrusted (it and Placide Boue (1832).This treatment became suspect looked like baked finish) in mica schist matrix and to early in the 20th century, though, and in 1919 Leonard have been hater washed or tumbled. The color was a Rosenthal wrote: "Must it be said that we tremble to slightly bluish green with a few inclusions of what ap- think of readers who would submit their pearls to the peared to be biotite as well as some mica, exceptionally treatment prescribed by the well-known doctor (de little jardin, and some very minor internal flaws. Boot)?" We cut a "window" on the smallest specimen and If the results obtained by Nassau and Hanson (e.g., this is where the fun started. On drying the rock, we on pearl no. 10) were not always as good as hoped, the noted that the paper had been stained a vivid yellow and cause is probably the thinness of the nacre layers in a that oozing out of the stone was a liquid which felt Japanese cultured pearl, as compared to the thickness of somewhat acidic (acetic acid to set dye?]to the hands. nacre in a natural pearl, for which the recipes were The balloon really went up when the stone was washed intended. Even a natural pearl must be carefully exam- in lukewarm water and household detergent-it came ined before peeling. The general consensus has been that apart completely, showing a green dye on the flat faces of it is not possible to peel cultured pearls, but the thick- what looked like a quartz material. Obviously the pieces ness of nacre in South Sea cultured pearls would appear had been glued together. to be sufficient to permit peeling. There are, in fact, two Our personal feeling is that someone read the men in Paris and one in New York (whostudied in Paris) literature on emerald and turned out a very credible who know how to peel pearls and feel that it is still a imitation. We were subsequently told that this fake valid technique. apparently came from Zimbabwe, where someone is It should also be noted that, contrary to the com- producing them in quantity. ment on p. 225 of Nassau and Hanson (19851, Halleux M. C. L. Backler did not compare the cleaning of pearls to that of a "fake Pinetown, South Africa gemstone." What he did was to use a dirtied imitation diamond and a duck to demonstrate the cleaning power of gastric juices in general. MORE ON OLD J.-P. Poirot PEARL-CLEANING RECIPES Director, Public Service for the Control of Diamonds, Pearls, The experiments of Nassau and Hanson (Winter 1985, and Precious Stones pp. 224-231) confirm the validity of the old Chaldean Paris Chamber of Commerce recipes compiled by Bolos of Mendes (among others) and Industry between 200 and 100 B.C.Although many of these old Paris, France

Editorial Forum GEMS & GEMOLOGY Summer 1986 105 CHINA'S BOUNDARIES (Tibet) takes the Aksayqin area out of China's territory. I felt that our cooperative paper ["A Survey of the Gemstone Resources of China" Gems d Gemology, I had sent a map to replace the draft you sent, and Spring 1986, pp. 3- 13, coauthored by Dr. Peter C. Keller] hereby suggest that you include it in the next issue of had an outstanding layout. However, I am sorry to have Gems 0) Gemology as a corrigendum. found the map showing the location of major gem occur- Wang Fuquan rences in the People's Republic of China to be unaccept- Geological Museum able because of the following political mistakes: of China, Beijing A. Chinese on both sides of the Taiwan Straits ac- cept Taiwan as a province of China, a fact that In the process of incorporating the information pro- has also been recognized by your government. vided by Dr. Wang and the additional localities sup- Taiwan, however, is colored as China's neigh- plied by Dr. Keller into a more comprehensive map, we boring country on the map. unfortunately did not pay adequate attention to the B. There are some boundary sections that are unac- political boundaries of the map Dr. Wang had provided. ceptable to China. For example, the eastern sec- We regret any embarrassment that this may have tion of the boundary between China and caused Dr. Wang, and direct our readers' attention to follows the illegal McMahon Line, and the the map draft originally submitted by him, reproduced boundary section west to Xingjiang and Xizang here as figure 1 .-Editor

Figure 1. Map of the principal gemstones of China prepared by Dr. Wang Fuquan. For clarification, we have shaded the areas discussed in Dr. Wang's letter.

- BOUT11IBLAN CHINA Ifi SEA

106 Editorial Forum GEMS & GEMOLOGY Summer 1986 WHAT IS A SYNTHETIC? they are man-made, they are, by definition, "syn- thetics." Many modern gemologists define synthetic (noun) as a Gemologists should stop using the word synthetic man-made substance which has the same physical prop- as a noun-it serves no useful purpose. Rather, synthetic erties and chemical composition as a naturally occur- should always be used as an adjective in conjunction ring mineral. This is incorrect. with the noun it modifies. Under these circumstances, The correct definition of the noun synthetic is there can never be any misunderstanding. something that is man-made rather than naturally oc- Although the definition expressed in the first para- curring. The operative word in this definition is man- graph is incorrect as a definition of the nounsynthetic, it made. Consequently, that which is not man-made is, by is correct as the definition of a "synthetic mineral." definition, natural. Consequently, we can apply it to the two glasses and Acceptance of the faulty definition in the first para- rightly conclude that they are not synthetic minerals. graph leads to the statement made in the Gem News As to what they are, there are many answers. They column (Summer 1985, p. 119) concerning Alexandrium may be called synthetic materials, synthetic glasses, or and Laserblue: "They are not classified as synthetics even simulated gems. In the gemological sense, these because they do not duplicate minerals." materials are "synthetics," but not synthetic gems or How then does one classify these substances? The synthetic minerals. In the commercial sense, they are report states that Alexandrium is a lithium aluminum salable products; however, since they are merely glass, silicate and Laserblue is a borosilicate. This statement is fancy names or pseudo-compositions cannot increase also incorrect. The terms silicate and borosilicate, by their intrinsic worth. definition, incorporate the concept of a defined crystal structure. These new materials are amorphous. In sim- W. W. Hanneman, Ph.D. ple language, these materials are glasses. Also, since Castro Valley, CA

Continued from p. 127 indexes and a bibliography of over fluid inclusions. Any gemologist 1,700 entries. who has ever enjoyed looking formed, and describes the changes From the gemologist's view- through the microscope will appre- that inclusions undergo after they point, the one drawback to this vol- ciate Dr. Roedder's effort. are sealed in their hosts. The prepa- ume might be the fact that the Considering the complex nature ration of samples for study and the microscope techniques as well as of today's synthetic and treated destructive and nondestructive much of the testing methodology gemstones, it is wise for the methods of inclusion analysis pres- (particularly the destructive tech- gemologist to learn as much as pos- ently in common use are discussed. niques) employed by Dr. Roedder and sible about inclusions in gem mate- Ways of interpreting the data ob- others in their investigation and rials. This excellent book provides a tained from fluid inclusions are out- documentation of fluid inclusions solid foundation for the study of fluid lined, and each of the various geo- are not directly applicable to routine inclusions in all materials, and logic environments, from sedimen- gemology. Even so, the chapters should be read by every serious tary to the upper mantle, is detailed providing a glimpse at these tech- gemologist. With over 400 black- in its own separate chapter. Even niques are fascinating. They not only and-white photographs and over 200 extraterrestrial environments are enlighten the gemologist to the line drawings and charts, this large discussed in a chapter that highlights complexity of the inclusionist's volume is a real bargain at $15.00. inclusions in both lunar rocks and problems, but they also introduce JOHN I. KOIVULA meteorites. The book also contains the sophisticated instrumentation Senior Gemologist comprehensive subject and locality often needed to genetically interpret CIA-Santa Monica

Editorial Forum GEMS & GEMOLOGY Summer 1986 107 EDITOR C. W. Fryer GIA, Santa Monica CONTRIBUTING EDITORS Robert Crowningshield LAB NOTES Gem Trade Laboratory, New York Karin N. Hurwit Gem Trade Laboratory, Los Angeles Robert E. Kane Gem Trade Laboratory, Los Angeles

Devitrified GLASS Cobalt-Bearing Recently submitted to the Los An- geles laboratory for identification was the 2.89-ct black free-form cabochon illustrated in figure 1. Our client explained that it was repre- sentative of material being exported from Hong Kong as black "onyx" (dyed black chalcedony]. When Figure 2. At 20 x magnification, viewed with the unaided eye in sun- the cabochon shown in figure 1 light or artificial overhead illumina- revealed a dendritic pattern tion, the piece appeared to be opaque Figure 1. This 2.89-ct black typical of man-made devitrified and black. However, when examined free-form cabochon, glass. Oblique illumination. under magnification with dark-field as dyed black and fiber-optic illumination, the chalcedony, was found to be edges of the cabochon appeared to be cobalt-bearing devitrified glass. major amounts of tin oxide and re- semitransparent to translucent, and melted with manganese oxide and blue in color. Also very prominent "hammer slag" from the production was the dendritic structure (figure2) 2.60. The hardness was estimated to of iron, this is the first time that we that is characteristic of man-made be between 5Y2 and 6% on the Mohs have encountered a black-appearing devitrified glass. This pattern is well scale. When the cabochon was placed cobalt-bearing devitrified glass. Per- known to gemologists, as it is typical on the diaphragm of the spectro- haps a major motivation for simulat- of the excellent devitrified glass imi- scope unit, or over the end of a fiber- ing dyed black chalcedony is that the tation of jadeite jade that is known as optic light source, the entire stone devitrified glass can be molded into a "metajade." Patterns such as these, "glowed" bright red because of the particular shape, requiring repolish- which are the result of devitrifica- very strong red transmission. ing only on the top. The back of the tion (the partial change of a sub- To view the absorption spec- devitrified glass cabochon described stance from an amorphous glassy trum, we placed a fiber-optic light here did show evidence of molding. structure to a crystalline, or partially tube directly behind the cabochon in R K crystalline, structure after solidifi- order to pass enough light through cation) should always alert the this very dark material. With the With an Unusual Inclusion gemologist to the probability of spectroscope, we observed a strong The New York laboratory recently glass. cobalt spectrum that was essentially examined two translucent green oval A spot refractive index of 1.50 the same as that for cobalt-bearing cabochons that were being repre- was obtained. The material was inert flame-fusion synthetic blue spinel. sented as natural glass from Mexico. to long- and short-wave ultraviolet However, the glass absorbed light up radiation. Since the cabochon was to nearly 480 nm and exhibited an nearly opaque in most lighting con- overall dark absorption pattern, ditions, no reaction was expected, or which is to be expected in stones that Editor's Note: The initials at the end ofeach item identify the contributing editor who observed, in the polariscope. The are extremely dark in color. provided that item. specific gravity was estimated with Although we have seen opaque heavy liquids to be approximately black glass imitations colored with 01986 Gemological Institute of America

108 Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 and porous areas of the stone. The same unnatural purple color in effect of the dye is to darken light patches not associated with cracks or areas and provide a more uniform ap- otherwise obviously porous areas. pearance. Some of the dyed stones Under a Chelsea color filter) the are further llsealedffwith some type beads all appeared a definite brown- of oil) wax) or the like. However) ish red, much brighter than any some paraffin-treated lapis (whether natural-colored specimens we have dyed or undyed] does "sweatff when tested. RC tested with a thermal reaction tester. Recently) a strand of 7-mm violet-blue beads known to be dyed OPAL (figure 41 was donated to the labora- tory. Unlike most of the dyed lapis Assembled Opal Beads we have examined, how'ever) these Anthony de Goutikre) a graduate beads were so heavily saturated that gemologist in Victoria) B.C., Canada) they virtually owed their color to thought our readers might be inter- dye. When exposed to long-wave ul- ested in an unusual opal bead neck- FigEdiu3. This distorted gas bubble in devitrified glass traviolet radiation) some of the beads lace he examined (figure 5). The resembles a partly resorbed showed a patchy red fluorescence; necklace is made up of cubic and with short-wave) only about half roughly spherical opal beads [7-15 crystal, SLIC~as is found in showed the chalky green fluores- mm in diameter] separated by trans- natural glass. Magnified 35 X. cence characteristic of natural lapis parent colorless faceted rondelles. As lazuli. Surprisingly) the liswabfltest figure 6 showsf however) the beads Yet the properties were the same as was not as revealing with these beads were actually assembled by attach- those for devitrified glass of this as with the selectively dyed stones ipg slices of opal to some sort of color) and $9 stones also showed the we have previously seen. However) shaped backing material with black dendritic pattern typical of man- the thermal reaction tester produced cement. These pieces were then cut made glais.i However, there was an evidence of paraffin treatment) so it and polished into shape. unusual inclusion (figure 31 near the may be that the paraffin "sealf1must The owners of the necklace surface on 'the back of one of the be removed before the dye will stain could not supply any information re- cabochons that resembled a partly the swab. Under magnification) a few garding its history) but guessed that resorbed crystal, suggestive of natu- of the beads showed purple dye in the it dated to the 1930s. This manufac- ral origin) although the high relief cracks) while others showed the turing technique represents an inter- and the rounded ends raised the pos- sibility that it might be a distorted Figure 4. These 7-mmlapis lazuli beads were heavily dyed and then gas bubble. Since the stones had been coated with paraffin. donated to the laboratory and the inclusion was so close to the surface) we scraped into the inclusion and found that it was hollowf proving that it was indeed only a distortedgas bubble. RC

LAPIS LAZULI, Dyed and llSealed" Over the years) the New York labora- tory has been asked many times to check for dye and) more recently) for evidence of oil or paraffin in lapis lazuli (see, for example, Gem Trade LabNotes section) Summer 1981 and Winter 1985). Heretofore) when ace- tone applied with a cotton swab has produced evidence of dye) the dye has been detected primarily in the cracks

Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 109 Figure 6. With 3 x magnifica- tion, it is evident that a black cement was used to attach slices of opal to a shaped Figure 5. The graduated (7-15 mmin diameter) opal "beads" jn this backing material to form the neclzlace were found to be assembled. opal "beads" shown in figure 5. esting way of using thin slices of opal dark yellowish green. Prominent tion spectrum (figure 8) that was vis- to create relatively large beads. CF dendritic black inclusions were eas- ible only through the longer optical ily visible to the unaided eye. At first path provided by the length of the Green Opal from Brazil glance! the material resembled trans- stone. There was general absorption A stone dealer recently brought to lucent green grossularite garnet. The up to 500 nml an absorption band at the Los hgeles laboratory a selec- refractive index was determined to 590-620 nml two distinct lines at tion of rough and cabochon-cut green be 1.43 (spot reading). Hydrostatic 640 nm and 670 nm, with a cut-off at opals from Brazil. Figure 7 shows the determinations of a11 three stones 690 nm. KH three sample stones (ranging from were made, with the average specific approximately 1 to 2 ct) that were gravity at 2.03k0.01. There was no donated to GIA. Both the rough and reaction to either long- or short-wave Cultured PEARLS, cut material was fairly translucent! ultraviolet radiation. The darkest Miscellaneous Oddities and the color varied from light to cabochon showed a peculiar absorp- The New York laboratory recently examined the 13-mm cultured pearl Fzgure 7 At first glance, these green opal cabochons (weighing 0 99, shown in figure 9. At first it was 2.22, and 1.84 ct, respectively) from Brazil resembled translucenf thought that the peculiar circular green gross~~farite area around the drill hole might be an insert. However! when viewed from

A .t -. the side! this circular area proved to be raised above the surface of the . .. pearl. It seems to match the size and 'L. configuration of the mounting cup

Figure 8. The absorption spectrum for the darlzest green opal cabochon shown in figure 7.

110 Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 that the pearl was once attached to. It is possible that the area around the cup was eroded by skin acid during wear! although the luster of the pearl does not seem to have been harmed. Some years ago! the New York laboratory was shown a group of pear-shaped pearls with oversized drill holes (figure lo). We subse- quently proved that they were freshwater mantle-tissue-nucleated Figure 9. This unusual circ~zlar cultured pearls on the basis of their area around the drill hole of (I X-ray fluorescence and because a few 13-mm cultured pearl is still retained vestiges, seen in the actually raised above the X-radiograph, of the l'voidl' caused surface of the pearl. Magni- by the mantle-tissue implant. Not a11 fied 10 x. pearls in a freshwater tissue-nuc- leated pearl necklace will show a Figure 10. Oversized drill holes void-some of the voids may be how this particular rutile manages to are often used to hide evidence eliminated by the drill holes. These exhibit such a sharp cat's-eye. Since of mantle-tissue nucleation in pearls create a problem when they the material is essentially opaque, it fresl~waiercultured pearls. are offered as natural pearls! the is unlikely that the chatoyancy is the seller hoping that the drill hole has result of reflection of light from par- eliminated the evidence of tissue allel acicular inclusions, as in chry- nucleation. The laboratory has en- soberyl and other materials. Al- ral blue llcobalt-coloredl' spinels. countered*suchpearls in old jewelry thoughl to our knowledgel rutile has Figu~e12 shows one of these stones! from whith the original natural not previously been reported to occur which weighs 2.21 ct and is an in- pearls have been removed and these in a massive fibrous form, this would tense "cobalt blue." The other stone pearls substituted. RC seem to be the only explanation for weighs 5.31 ct and is dark violetish its ability to produce a cat's-eye blue. These two stones exhibit es- effect. CF sentially the same gemological char- acteristics as the 2.56-ct natural Cat1s-Eye RUTILE spinel mentioned in the Gem Trade A local gemologist and dealer in Lab Notes section of the Winter 1982 pearls and rare gemstones asked the issue of Gems e3 Gemology, and the Research Department of GIA-Santa natural blue cobalt-bearing spinels Monica to identify two cat's-eye discussed in great detail in an article stones (2.74 ct and 1.43 ctJ that his by J. E. Shigley and C. M. Stoclzton firm had acquired in Sri Lanka. The that appeared in the Spring 1984 stones were opaque and appeared to issue of Gems ed Gemology. The ab- be black, although the sharp eyes in sorption spectra of the stones Shigley each were brown (figure 111. Gem- and Stockton studied have character- ological tests done by the client re- istics that are generally attributed to vealed the refractive index to be over cobalt and iron. The samples used in the scale (greater than 1.81J1 and the that study' which included both specific gravity to be considerably rough and cut stones! were report- heavier than the 3.32 liquid. The Figure 11. This unusual cat's- edly from the Olzkampitiya mining stone gave no reaction when exposed eye rutile weighs 2.43 ct, region of Sri Lanka. These unusual to either long- or short-wave ultra- Magnified 3 X. natural spinels represented a type violet radiation. The streak was that was new to most gemologists, in brown and the hardness seemed to be that blue coloration caused by cobalt about 6 or a little higher. The X-ray was previously believed to occur diffraction pattern obtained from a only in synthetic, not natural! spinel. liCobaIt-Blue'' SPINEL, minute amount of powder scraped Although this type of natural an Update from the back of one stone matched blue llcobalt-colored'' spine1 is very that of rutile. The Los Angeles laboratory recently unusual and may be encountered It is interesting to speculate on received for identification two natu- only rarely by the jeweler-gemol-

Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 111 flame-fusion synthetics of this color. tained several well-formed transpar- With the spectroscopel we observed ent crystals which showed moderate bands at approximately 434) 460, interference colors under polarized 480,559, 575) 595) and 622 nm [for an illumination. These crystals had the illustration of a similar spectrum) same appearance as those observed see the article in the Spring 1984 in other natural l'cobalt-bluell issue of Gems et? Gemology]. The spinels. In addition, small cavities most diagnostic spectral features are and fractures with yellow stains the bands at 434, 460) and 480 nml were also present. The 5.3 1-ct stone which do not occur in the synthetic contained a group of white, irregular! material. The 2.21-ct spinel con- thread-like inclusions along a heal-

Figure 12. A 2.21-ct nat~lral Figure 13. Testing with a hot point revealed that thesurfaceof this turq~~ojse "cobalt-colored" blue spinel. carving (12.4 x 11.0 x 8.6 cm een treated with paraffin. ogist) it can be readily identified by its characteristic properties. The specific-gravity values for the two spinels that we recently examined were within the expected range for both natural and synthetic blue spinel. The refractive index, 1.7201 is consistent with other natural blue spinels. The two spinels were inert to both long- and short-wave ultravio- let radiation. This is in contrast to flame-fusion synthetic "cobalt- blue1' spinel, which often exhibits a strong chalky whitish green fluores- cence to short-wave ultraviolet radi- ation and a strong red fluorescence to long-wave ultraviolet radiation. The color-filter reaction of this type of natural spinel (weak to strong red) can overlap with that of its flame- fusion synthetic counterpart. Exam- ination of the two spinels with a po- lariscope revealed that they were singly refractive with very little, if any) anomalous double refraction. This is in contrast to the strong 'tcross-hatchedl' patterns and/or "snake-liketJ bands present in flame-fusion synthetic blue spinels. When the 2.21-ct spinel was placed over the opening of the iris dia- phragm on the spectroscope unit) no colored transmission was observed) whereas a very weak red transmis- sion was seen in the 5.31-ct stone. Examination of several other natural blue cobalt-bearing spinels has re- vealed that some may exhibit a strong red transmissionl as do many

112 Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 ing plane; some were stained brown- was obtained on most areas of the ish yellow by iron. We have also carving. We scraped away the paraf- observed this type of inclusion in fin on a small area at the base of the other natural f'cobalt-bluettspinels. carving and obtained a refractive index of 1.611 which is typical for turquoise. In addition to the colorless par- affin treatment, matrix was simu- TURQUOISE, with Simulated lated by the use of a black dye in the Matrix paraffin (see figure 14). The black Recently brought to the Los Angeles matrix was cleverly daubed on to laboratory for identification was the many surfaces of the carving opaque greenish blue carving of two and was only rarely added to natural Oriental women illustrated in figure matrix depressions. R K 13. Testing identified the carving as paraffin-treated turquoise. A hot point on a low setting caused the FIGURE CREDITS paraffin to melt profuscly. When the The photos in figures 3 and 11 were laken piece was examined with magnifi- by John I. Koivula. Shane McClure pro- cation) both the color and structure Ivided the pholomicrographs used in fig- were found to be typical of porous Fig~zre14. Blaclz dyed paraffin ures 1, 2, and 12-14. Dave Hargett was turquoise from China (porous tur- was used on the turq~~ojsc responsible for figures 4 and 9, and Chuck Fryer took figure 7. Figures 5 and 6 are quoise from any locality can be par- carving shown jn figure 13 to qourtesy of Anthony de Goutiere. Bob affin treated]. A spot refractive index sin~ulatenatural matrix. Crowningsh~eld gave us figure 10, and of 1.58) w*hich is low for turquoisel Magnijie~f5 X. Karin HurwIt prepared figure 8,

- - Whatever you need to know t gems and jewelry will find at the GIA Bookstore Books Slides * Periodicals Audio & Video Tapes Send today for the FREE GIA Bookstore Catalog or call TOLL FREE 800-421-7250. In California, 213-829-3126.

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Gem Trade Lab Notes GEMS & GEMOLOGY Summer 1986 113 John I. Koivula, Editor Elise Misiorowski, Contributing Editor

COLORED STONES Spot refractive index readings of 1.51 and 1.70. Tucson 1986. In addition to the many extraordinarily Extremely high birefringence suggests a carbonate. fine natural gemstones such as rubies, emeralds, sap- The specific gravity of magnesite, approximately phires, tanzanites, garnets, aquamarines, tourmalines, 3.0, is too high for calcite (2.7 1)or dolomite (2.851, topaz, and the like, usually seen at Tucson, this year's both of which are also frequently used to sim- show featured many other interesting gem materials. ulate turquoise. Once the material has been Robert E. Kane, gem identification and research super- identifiedas magnesite, it is immediately evident visor for GIA1s Gem Trade Laboratory in Los Angeles, that it is dyed, since blue magnesite does not supplied the following report on some of the more un- occur naturally. usual materials seen at the February 1986 Tucson Gem Not only is the magnesite dyed, but the recessed and Mineral Show for Gem News. matrix areas in these tumbled nodules are filled with a wax-based black material (probably added during the Cat's-eye kunzite. Chatoyant semitranslucent to polishing process) to imitate spiderweb turquoise. opaque kunzite cabochons and rough from a deposit in South Dakota were displayed. Pectolite. A large selection of rough and cabochon-cut blue pectolite from the Dominican Republic was dis- Covellite. Several firms were selling massive forms of played by a dealer from Santo Domingo who claims to covellite rough, as well as cabochons and faceted tablets. control the entire supply of this material from that Covellite (CuS)is generally dark indigo blue in color, source. This attractive translucent-to-opaque blue or- sometimes with a purple surface tarnish. Covellite has a namental mineral usually shows one or more fibrous submetallic luster, a specific gravity of about 4.6, a shade radial patterns. It has been known for several years by or spot refractive index reading of 1.45, and a hardness of the trade name "Larimar," but this is the first effort we 1.5-2. It is frequently intergrown with small veins of have seen to market it on an international scale. "brassy" metallic-appearing minerals such as pyrite and chalcopyrite. Covellite cabochons are usually inexpen- "Rainbow" moonstone. Several dealers had cabochons sive and sold as a collector's stone. Because of its from India that were described as "rainbow" - softness-it can be scratched with a fingernail-covel- stone. The cabochons were small, ranging from 1 to 2 ct lite is not used in jewelry. each. This unusual type of "white" moonstone displays an attractive adularescence of orange, pink, green, and Lepidolite. One dealer had about 50 cabochons of blue, in contrast to the predominantly blue-white lepidolite, some as large as 20 ct. Most of the cabochons adularescence generally associated with moonstones of were opaque, ranging in color from light to dark pinkish this body color. These stones were always displayed on a purple, and nearly all appeared to be identical to the black background, which accentuated the multicolored lepidolite "matrix" that occurs in massive quantities at adularescence, and were most impressive when several several of the tourmaline deposits in Pala, California. A were placed together. few of these stones, however, were translucent. A medium-dark pinkish purple stone revealed shade re- Spurrite. Numerous pieces of rough and a few polished fractive indices of around 1.560- 1.590, a specific gravity slabs of an attractive translucent to opaque, medium to of about 2.8, and a hardness of approximately 3. It was dark purple gem material were displayed by a dealer in inert to long-wave ultraviolet radiation, and fluoresced Tucson who sells gems and minerals from Mexico. He extremely weak to short-wave U.V. rays. said that he had just over 100 kg of rough. Apolished slab of this material was tested, and revealed shade refractive Magnesite dyed blue to imitate turquoise. One dealer indices of 1.640- 1.680, a hardness of around 5, and a was selling necklaces of tumbled nodules of dyed blue specific gravity near 3.0, all of which matched those magnesite from Africa. This material can be identified properties recorded for the mineral spurrite. by the following: X-ray powder diffraction analysis by C. W. Fryer of

114 Gem News GEMS & GEMOLOGY Summer 1986 Figure 2. When this 18.57-ct rock crystal quartz was cut, a single included acicular black tourmaline crystal was carefully positioned so that its reflection would create the wagon-wheel pattern evident here. Photo by John Koivula.

Figurn 1. This rare natural twin star spinel weighs (ISA), and the American Gem Trade Association 2.22 cl. Note the twin plane running down the (AGTA) present many industry-related seminars and center of the stone. Photo 0 Tino Hammid. short courses. *<, . !. Twinned star spinel. One of the most striking gems we the GIA Research Department confirmed that this at- have seen in a long time is shown in figure 1. This tractive purple gemmy material is spurrite. Dana's pinkish purple natural star spinel weighs 2.12 ct and Textbook of Mineralogy states that spurrite, belongs to David Myerson of Northridge, California. Ca5(Si04)i(C03),occurs in contact zones between lime- Fine star spinels are not particularly common, and this stone and diorite in the Valardena mining district of one is a rarity among the rare. The gem is divided down Mexico, as well as in Ireland. the middle by a twin plane and its surrounding contact Taaffeite. Two unusual taaffeite crystals were exam- zone. This contact zone is darker than the rest of the ined. One, a distorted crystal weighing 46.17 ct, is the stone and contains no star-producing inclusions. As a largest known piece of taaffeite rough ever recorded. The result of the contact twinning, two complete and dis- other weighed 2.81 ct and had several fairly well tinct stars are readily visible, one on each side of the developed crystal faces, which has never before been twin plane, even when just a single light source is em- reported in taaffeite. ployed. This is the only twinned double-star spinel we have ever encountered. The Tucson show always provides an opportunity to see and examine rare collector stones that have been Wagon-wheel quartz. Don Riffe, of Wight Jewelers in cut. In addition to those already listed above, excellent Ontario, California, gave us a most unusual faceted rock examples of the following were also seen this year: ekan- crystal quartz for examination. It weighed 18.57 ct ite, phosphophyllite, proustite, friedelite, haiiyne, (15.88 x 13.69 mm)and was well fashioned in a modified pyrargyrite, bustamite, light blue and brown sillimanitc round step-cut. The unusual feature of this quartz is that (fibrolite), and purple scapolite. it contains a single acicular crystal of black tourmaline. Collectors, retailers and dealers say that the Tucson The cutter, John Boardman, has positioned the tourma- show helps pinpoint market trends in colored gem- line inclusion so that it runs from the culet through the stones, supplies, and price changes, and provides an op- entire depth of the stone up to the center of the table. As portunity to see and purchase all types of rough and cut shown in figure 2, the black tourmaline inclusion is gemstones, jewelry, and mineral specimens, as well as reflected in a spoke-like pattern in the quartz, creating lapidary equipment and tools. Another important aspect the appearance of a wagon wheel. In the past, the editors of the Tucson show is the opportunity for structured have seen a few similar stones that have used either education. In addition to GIA1s lectures and seminars, tourmaline or rutile as the reflecting crystals. Good other groups such as the Accredited Gemologists Asso- rough to cut such stones is difficult to obtain, and is ciation (AGA), the International Society of Appraisers generally referred to as single-needle quartz.

Gem News GEMS & GEMOLOGY Summer 1986 115 Sams Collection now on display at institutions, and members of the the Houston Museum of Natural appraisal profession. The committee Science. The Houston Museum of will also formulate the educational Natural Science recently purchased curricula for appraisers of personal the Perkins and Ann Sams collection property leading to academically of minerals. to be housed as a recognized bachelors' and masters' permanent exhibit in the new Lillie degrees in Valuation Sciences. and Roy Cullen Gallery of Earth Science. The collection encompasses The India Gems & Jewellery Fair some 500 mineral specimens, will be held at the Taj Mahal Hotel, including a superb imperial topaz in Bombay, India, September 4-8, crystal from Brazil; a grouping of fine 1986. Organized by the Gem & tourmaline specimens; cerussiteand Jewellery Export Promotion Council azurite from Africa; emerald, ruby, and the Hindustan Diamond and diamond crystals; and fine pieces Company, Ltd., the fair will feature of Japanese stibnite, German unmounted diamonds, colored manganite, and Bohemian stones, and pearls, as well as cassiterite. A particularly fine traditional, antique, and emerald crystal from the collection contemporary jewelry. For further is shown in figure 3. information contact: I.G.J. Fair 1986, For further information, contact c/o Hindustan Diamond Company, the Houston Museum of Natural Ltd., 15, Atlanta, Nariman Point, Science, 1 Hermann Circle Drive, Bombay, 400 021 India. Telex: 01 1- Hermann Park, Houston, TX 77030; 4710 HDCL IN. (713)526-4273. Figure 3. This fine emerald with INTERGEM '86, the International GIA GemFest scheduled. GIA will pyrite specimen (45 mmhigh)- Trade Fair for Gems & Jewellery, hold its third annual GemFest on from Muzo, Colombia-is part will be held on September 26-29, August 14 and 15, 1986, at their of the famous Sams Collection 1986, in Idar-Oberstein, West Ger- headquarters in Santa Monica. now housed in the Houston many. The exhibits range from min- GemFest is a program of seminars Museum of Natural Science. eral specimens and gem rough to fin- encompassing gemology, jewelry Photo Cl Harold ed Erica ished jewelry, andproducts related to manufacturing arts, jewelry sales, Van Pelt. the jewelry industry. For further in- and business. For registration and formation contact: INTERGEM further information, contact GIA GmbH, Messeverein e.V., Postfach GemFest, 1660 Stewart Street, Santa diamond, designed by Vikki Jirikow 12 21 80, D-6580 Idar-Oberstein, Monica, CA 90404; (213)829-2991. of Playa del Rey, California. West Germany. The deadline for the 1987 Winners of the Scheutz Award competition is February 28,1987. For The Fourth Hong Kong Jewellery & Design Contest announced. The further information, contact the Watch Fair will be held September George A. Scheutz Memorial Fund Jewelry Manufacturing Arts 13-16, 1986, at the Regent, New Jewelry Design Contest added a new Department at GIA-Santa Monica. World, and Sheraton Hotels and the category this year for its annual Golden Mile Holiday Inn. Over 400 competition hosted by GIA. For the Committee formed by ASA and AAA exhibitors from 22 countries around past 10 years, the competition has to establish uniform appraisal the world will offer a wide range of featured men's jewelry and standards. The American Society of products for all aspects of the gem, accessories only. This year, women's Appraisers and the Appraisers jewelry, and watchmaking colored stone jewelry was added. The Association of America have industries. Seminars on the winning entries, submitted in the announced the establishment of a international market situation and form of color renderings, are: a joint committee to create and various other topics will be held woman's ring of 18K yellow gold and produce uniform standards of concurrently with the fair. For lapis lazuli designed by Catherine 0. appraisal practice specifically for the further information contact: Villeneuve of Villeneuve-Lamarche, appraisal of personal property, in Headway Trade Fairs Ltd., 628 Star Montreal, Quebec; and a man's 18K order to provide guidelines that can House, 3 Salisbury Road, Kowloon, yellow-gold ring inlaid with onyx be used by the public, the courts, Hong Kong. Tel.: 3-697993; telex: and set with a quadrillion-cut government agencies, commercial 41249 HX.

116 Gem News GEMS & GEMOLOGY Summer 1986 GEMOLOGICAL ABSTRACTS

Dona M. Dirlam, Editor

REVIEW BOARD

William E. Boyajian Gary S. Hill Michael P. Roach GIA, Santa Monica GIA, Santa Monica Andin International. New York Jeffrey M. Burbank Steve C. Hofer Gary A. Roskin GIA, Santa Monica Kensington, Connecticut GIA, Santa Monica Stephanie L. Dillon Karin N. Hurwit James E. Shigley San Clemente, California Gem Trade Lab, Inc., Los Angeles GIA, Santa Monica Bob F. Effler Robert C. Kammerling Franceye Smith GIA, Santa Monica GIA, Santa Monica GIA, Santa Monica Joseph 0. Gill Neil Letson Carol M. Stockton Gill & Shortell Ltd., San Francisco Palm Beach, Florida GIA, Santa Monica Fred L. Gray Shane F. McClure Sally A. Thomas Richter's, Georgia Gem Trade Lab., Inc., Los Angeles GIA, Santa Monica Mahinda Guhawardene Elise B. Misiorowski Jill M, Walker Idar-Oberstek, Germany GIA, Santa Monica Issaquah, Washington -

COLORED STONES AND Fritsch is an excellent review of how color arises in gems ORGANIC MATERIALS and minerals, with easy-to-understand cxplanations of atomic-level behavior. In the first article, Dr. Fritsch La couleur des min6raux et des gemmes (The color of discusses single-element color origin associated minerals and gems). E. Fritsch, Monde et Mjner- primarily with transition-metal ions, including expla- aux, Vol. 22, Nos. 67, 69 and 70, 1985, pp. 20- nations of valence states, site coordinations, and distor- 25, 12-17, and 12-22. tions. Examples of how each of these variables affects While the colors of gems and minerals contribute greatly color and the optical absorption spectrum are clearly to their appeal, the causes of these colors provide clues described, and a list is provided of common transition- to the genesis of the different materials. An understand- metal ions and their coordinations, together with the ing of color origin also provides a foundation for the color generated by each and the minerals in which each better use of spectral and luminescence tests for gem occurs. identification. This trio of articles by Dr. Emmanuel The second article covers the more complex cases of charge transfer and interband transitions, with explana- tions of the molecular orbital and band gap theories necessary to understand these color origins. Normally This section is designed to provide as complete a record as relegated to the realms of advanced physics and chemis- practical of the recent literature on gems and gemology. Articles try, these scientific theories take on a more elementary are selected for abstracting solely at the discretion of the section editor and her reviewers, and space 1im;tations may require that tone with Dr. Fritsch's explanations and the numerous we include only those articles that will be of greatest interest to our graphs and drawings that accompany them. The third readership. article concludes the series with discourses on color Inquiries for reprints of articles abstracted must be addressed to centers, diffraction, iridescence, Tyndall effect (scatter- the author or publisher of the original material. ing), and diffusion, including chatoyancy and asterism. The reviewer of each article is identified by his or her initials at the On the whole, this series of articles provides an end of each abstract. Guest reviewers are identified by their full excellent overview of the causes of color in gems and names. minerals, with intelligible explanations of complex 07986 Gemological Institute of America concepts. Lavish color photographs by Nelly Bariand and numerous helpful diagrams accompany the text.

Gemological Abstracts GEMS & GEMOLOGY Summer 1986 117 Many of the illustrations, however, are neither num- bonded to the silica framework at structural defects, bered nor directly referenced in the text, which is irritat- while type B involves surface silanole groups that are ing and results in a lot of looking back and forth for most likely hydrogen bonded to similar neighboring associations. Nevertheless, the major drawback of the groups. Type B represents only one-third of the chalced- article for many GeIG readers will be that it is entirely ony silanole groups, but it represents almost all of the written in French. It is to be hoped that Dr. Fritsch will 'water" in opal-C. All crystal surfaces are covered with soon render a version in English. CMS silanole groups hydrogen bonded to molecular water. Chalcedony bands ranging from translucent gray to Crystal chemistry of zincian spinels (gahnospinels)from milky white were found to correspond to a decrease in Sri Lanka. K. Schmetzer and H. Bank, Neues total water content, molecular water content, and spe- Jahrbuch fur Minerulogie Monatshefte, No. 8, cific surface, together with an increase in density. 1985, pp. 353-356. Molecular water content also decreases with hy- The chemical composition, density, and refractive index drothermal treatment, which indicates a variable low- of zincian spinels from Sri Lanka have been investigated. temperature formation for this Brazilian agate: below All samples were transparent gemstones of a blue, blu- 250° and 0.5 kilobars, and possibly also at room tem- ish violet, or violet color caused by the presence of Fez+ perature and pressure. Emmanuel Putsch substituting for Mg2+ in the tetrahedral site. These stones are members of a compositional series between Zirkon-Katzenauge aus Sri Lanka (Cat's-eye zircon from spinel (MgAlZO4)and gahnite (ZnA120a)in which the Sri Lanka). H. J. Mullenmeister, Zeitschrift der molecular percentage of gahnite varies from 0.2% to Deutschen Gemmologischen Gesellschaft, Vol. 50.35%) with minor amounts of a hercynite (Fe2+A1204) 34, No. 3/4, 1985, pp. 165- 166. component ( 1.7% to 5.37%) also present. Density in- The author reports on the identification of a cat's-eye creases with zinc content from 3.60 (pure spinel) to 4.05 zircon that had been represented as a moonstone from (50% gahnite), while the refractive index also increases Sri Lanka. The specific gravity was determined to be correspondingly from 1.716 to 1.752. 4.62, and the spectroscope revealed an absorption spec- This study confirms what is already known about trum identical to that of zircon. The radioactivity of the this material, and substantiates the existence of a com- sample is also mentioned. MG plete solid-solution series in the spinel-gahnite compo- sitional range. Emmanuel Putsch Zur mineralogischen und chemischen Zusammenset- zung des Schmucksteins Verdit aus Sudafrika Farbloser Skolezit aus Indien (Colorless scolecite from (Mineralogical and chemical composition of the India). H. Bank, Zeitschrift der Deuischen Gem- gemstone verdite from South Africa). F. Rost, J. mologischen Gesellschaft, Vol. 34, No. 3/4, 1985, Wannemacher, and 0. Krebs, Neues Jahrbuch fur pp. 167-168. Mineralogie Monatshefte, No. 9, September 1985, Colorless, transparent crystals represented as natrolite pp. 427-432. were identified as scolecite by refractive indices of n, Verdite is a green opaque rock that has been used for 1.512, n 1.518, n; 1.523, and a birefringence of 0.01 1. centuries by South African natives for mystical pur- The specific gravity is given as 2.21. Scolecite usually poses. However, it was only "rediscovered" as a occurs as radiating fibrous masses in volcanic rocks in gemstone at about the turn of this century. Rio Grande do Sul, Brazil, and in Poona, India. MG Five verdite specimens from the Baberton District, Transvaal, South Africa, were studied using chemical The nature of water in chalcedony and opal-C from analysis and X-ray diffraction, together with conven- Brazilian agate geodes. H. Graetsch, 0. W. Florke, tional microscopic observation. Fuchsite (chrome- and G.Miehe, Physics and Chemistry of Minerals, muscovite) is the most important mineral and the main Vol. 12, 1985, pp. 300-306. chromium-bearing phase (2% to 4% Cr203),and there- Chalcedony and opal-C (cristobalite)in Brazilian agates fore gives verdite its bright green color. Both colorless (Rio Grande do Sul) have been investigated for their chlorite (clinochlore) and a plagioclase feldspar (near water content and speciation using differential thermal albite) may be present in significant amounts. A rela- analysis (DTA), gravimetry (DTG),and infrared spec- tively constant Ti02 content of about 1% is due to the troscopy, together with water titration, and specific presence of rutile crystals or their alteration products. surface and density measurements. The iron content is always very low (~0.1%Fe203]. Chalcedony and opal-C contain molecular water Unusual inclusions are light-colored tourmaline and, in adsorbed in multilayers on the crystal surfaces, fully the absence of a calcium-containing plagiolase, margar- hydrating the open porosity. They also exhibit two types ite (a calcium-containing mica). of differently bonded 0-H groups (hydroxyls]: The Verdite occurs as a secondary rock in basaltic ex- Si-0-H groups (silanoles)of type A are weakly hydrogen trusions in many South African localities. The high

118 Gemological Abstracts GEMS & GEMOLOGY Summer 1986 chromium content is attributed to enrichment through Winston acquired the stone, having paid "in the vicinity hydrothermal solution circulations, leaching, and con- of several million dollars" for it, well in excess of any of centration of this element from the underlying the previous bids. komatiites. Emmanuel Fritsch The original rough yielded 17 stones totaling 238.48 ct. The largest stone to emerge from the initial cutting was a 143.20-ct emerald cut. However, the stone was DIAMONDS flawed, and Winston eventually had it recut into seven Diamond exploration in Western Australia. C. L. Geach, stones, the largest of which was a 53.96-ct flawless pear Geology Today, Vol. 2, No. 1, 1986, pp. 16-20. shape. BPE In the early 1970s, major discoveries of diamonds were made in Western Australia in two principal areas- Over the years with De Beers. R. Shor, Jewelers' between Derby and Kununurra in the northern part of Circular-Keystone, Vol. 157, No. 2, 1986, pp. the state (Argyle and Ellendale], and a smaller area far- 340-343. ther south near Carnarvon. These finds are important In the past 15 years, De Beers has increased its advertis- not only for their magnitude but also for the fact that the ing budget almost 10-fold, and as the socio-economic host rock of the diamonds is not kimberlite as in South climate of the United States has changed, so has the Africa but rather lamproite. focus of their ads. Lamproites are a group of fine- to medium-grained In this fascinating article, Mr. Shor shows that ultramafic to mafic rocks that are rich in K, Ti, and Mg. while De Beers's ads have retained the image of romance The mineral content of lamproite thus differs from that and elegance, they have slowly shifted focus among vari- of kimberlite (as, consequently, do the mineral inclu- ous consumer groups, almost imperceptibly guiding the sions in the diamonds that each hosts).Kimberlites con- baby-boomers to adulthood. In the early 1970s, the main tain olivine, garnet, ilmenite, phlogopite, calcite, visual thrust of their advertising was aimed at mid- to clinopyroxene, and serpentine. In contrast, lamproites high-income custohers, but was tempered with the consist of, leucite, phlogopite, clinopyroxene, am- message "A gift of diamonds need not be expensive. phibole, oliyine, and sanidine. Your jeweler can show you exciting pieces under $200.'' At the more northern, and more economically im- De Beers also created the concept of the eternity ring, portant, of the two recent diamond discoveries in West- which was originally aimed at former flower children ern Australia, the deposits are located in belts of highly who had begun their pursuit of success. Later renamed deformed sedimentary and metamorphic rocks. These the anniversary ring, it now accounts for 25% of all belts rim the Kimberly craton, a large area of ancient diamond jewelry sales. granitic rocks of Precambrian age. This geologic setting Today the message is "Show her it's not lonely at is entirely different from that of other known diamond- the top. A diamond of a carat or more." Men's diamond producing areas. The present article summarizes the jewelry is also being promoted to a new, consumption- radical changes in conceptual thinking and in the strat- conscious generation. egy of diamond exploration in Western Australia that The changes have not come cheaply. In 1985, De resulted from this new kind of diamond occurrence. The Beers's advertising budget soared to $34 million, with major difficulties encountered in bringing a new deposit 44% invested in television spots (compared to $4 mil- from initial discovery to eventual full production, espe- lion in 1970 and no television ads). But this campaign cially the length of time required, are also discussed. /ES has paid off: During the last 15 years, sales have jumped from $800 million to $8 billion per year. Famous diamonds of the world (XVIII): the Star of Sierra Patricia A. S. Gray Leone. 1. Balfour, Indiaqua, Vol. 37, No. 1, 1984, pp. 129-131. GEM LOCALITIES This installment on famous diamonds recounts the dis- covery and eventual disposition of the largest diamond The occurrence of botryoidal and gem-quality nephrite ever recovered from an alluvial source: the Star of Sierra in Monterey County, California. T. R. Paradise, Leone. On February 14, 1972, the 968.9-ct rough dia- Journal of Gemmology, Vol. 19, No. 8, 1985, pp. mond was recovered from the picking table at the sepa- 672-681. ration plant operated by the National Diamond Mining Mr. Paradise briefly discusses the geology, mineralogy, Company of Sierra Leone (Diminco]near the Kono-area and gemology of the nephrite occurrence at Jade Cove, diamond fields. in Monterey County, California, and how to success- Diminco asked that De Beers CSO handle the sale of fully locate the nephrite at the site. the stone via a sealed bid. However, when the bids were Nephrite, an isomorphic product of the actinolite- opened on July 18, 1972, none of them had reached the tremolite series, usually consists of randomly oriented diamond's reserve price. In October of that year, Harry interlocking and interwoven fibrous crystals. However,

Gemological Abstracts GEMS & GEMOLOGY Summer 1986 119 the material found at the Monterev occurrence formed detailed, starting with the discovery of the first deposit in botryoidal masses. These flattened, oval-shaped in 1825. Included are famous finds such as the "Grotta masses typically consist of only two to 10 nodules each, dlOggi," a grotto that yielded many spectacular tourma- and are easily separated from the surrounding minerals, line crystals. Emmanuel Fritsch which are massive in form. Some of these nodular bun- dles have been so weathered that they are covered with a INSTRUMENTS AND TECHNIQUES layer of reddish brown oxidized material or "skin" Distinction of natural and synthetic rubies by ultravio- which may deceive uninformed collectors. The nephrite let absorption spectroscopy-possibilities and also occurs as polished pebbles. limitations of the method. K Schmetzer, Jade Cove is located between Plaskett Point and Zeitschrift der Deutschen Gemmologischen Cape San Martin, about 100 km south of the city of Gesellschaft, Vol. 34, No. 3/4, 1985, pp. 101 -129. Monterey. The nephrite can be found in the detritus below the greenish colored cliff areas, which represent The use of certain features in the ultraviolet spectra to the serpentine from which the nephrite has eroded. identify natural and synthetic rubies was first suggested David C. LeRose by Bosshart in 1981. He recognized differences in ultra- violet transparency between natural and synthetic ru- bies. He also suggested a numeric interpretation of the Les quartz sceptres de Denny Mountain (The quartz absorption spectra of these stones in terms of three scepters from Denny Mountain). B. Jackson, measured parameters associated with the location of the Monde et Mineraux, Vol. 23, No. 71, 1986, pp. minimum absorption in the ultraviolet. Graphic repre- 20-23. sentations of these parameters revealed separate popu- Four years ago, the most spectacular (up to 10 cm long) lation areas for natural rubies of different origin as well amethyst double scepters in the world were found by the as for synthetic rubies of various manufacture. This author and an associate at Denny Mountain, near method was suggested to be valuable in distinguishing Seattle, Washington (a scepter is a crystal that has a natural from synthetic ruby. second, wider crystal overgrown in a parallel way at its Since the publication of Bosshart's work, the diag- termination).At this locality, quartz crystals are formed nostic value of this identification method has been along veins caused by the percolation of hydrothermal called into question by the appearance of some synthetic solutions through an iron-bearing skarn. This article rubies whose parameter values fall near or within the describes in a very lively style this unusual mining en- population field of natural rubies on Bosshart's graphs. terprise. The quartz vein is located on a cliff in Red Wall This uncertainty led to a thorough reexamination of the Canyon, a very dangerous area where nine mountain Bosshart method in the present study. climbers have died within the past few years. Jackson Spectroscopic and chemical (XRF] data were col- describes the hazards involved in mining the deposit. lected for some 900 rubies from 15 localities and nine Even the men and equipment had to be brought in by manufacturers. Results of this study indicate that natu- helicopter. After 10 weeks of unrewarding digging, 40 ral and synthetic rubies exhibit several types of absorp- specimens of this unusual material were recovered from tion spectra that vary slightly in the location, shape, and this attempt. Emmanuel Fritsch intensity of their spectral features. Many of these spec- tra are illustrated in the 45 figures included in this arti- Les tourmalines de Pile dfElbe (Tourmalines from Elba cle. Some of these spectra types appear to be unique for a Island). S. Lareida, Monde et Mineraux, Vol. 23, particular natural or synthetic ruby, and hence are of No. 71, 1986, pp. 4-7. diagnosticvalue when working with a ruby of unknown The tourmaline deposits of Elba ()are located in the origin. It is concluded that the Bosshart method has two western part of the island, near Monte Capanne. They principal weaknesses as an identification test. The ad- are found in hydrothermal pegmatite veins that intrude vantage of the method as a simple procedure using only the granodiorite massif. The article emphasizes the col- three parameters is offset by the loss of further impor- oration of Elba's tourmalines, which are often color tant information, such as the positions of weak absorp- zoned perpendicular to the principal axis; most notable tion bands and shoulders, that is readily apparent from of these zoned crystals is the "Moor's head" (a clear an examination of the spectral patterns themselves. In prism with a black termination]. addition, a documented overlapping of population fields Light violet to pinkish to carmine red crystals con- of Bosshart's parameters for various natural and syn- tain no sodium, but have appreciable amounts of iron, thetic rubies prevents a clear determination of the origin lithium, and potassium. Brown to orange or yellow va- of a ruby. This is especially serious in the case of cer- rieties have a high sodium content. Green ones exhibit tain new synthetic rubies whose parameter values fall the highest amount of manganeseand sodium. There are within the natural ruby field on Bosshart's graphs. Thus, also blue, black, and colorless stones. theBosshart method has limitations as a diagnostic test. The history of tourmaline exploitation on Elba is The author suggests that ultraviolet absorption

120 Gemological Abstracts GEMS & GEMOLOGY Summer 1986 spectra can be of value in the identification of rubies of ber required depends on the type of work being done and unknown origin. However, this requires a direct com- the degree of fineness that must be determined. Touch parison of the spectrum of the ruby in question with acids are essentially composed of "nitric acids of differ- standard spectra of natural samples of known origin and ent strengths with or without the addition of copper or synthetic samples of known manufacture such as those sodium chloride, or hydrochloric acid." illustrated in the article. In many instances this will The text gives step-by-step instructions for per- provide a good indication of the ruby's locality or pro- forming the tests with 23 color photos as examples of ducer, or at least will reduce the number of possibilities. what the rubbings and acid reactions should look like. Even when the origin remains uncertain, examination of The authors, both assayers with the Swiss Federal Bu- the spectra in combination with microscopic observa- reau for the Control of Precious Metals, emphasize that tions and, if necessary, with chemical (trace element] touchstone testing "requires specialized knowledge and data, will often provide a clear determination. JES considerable experience that can only be acquired through practise." The authors' addresses are pro- Uber die Problematik der Galliumgehalte als Hilfsmit- vided so that the reader can contact them for further tel zur Unterscheidung von naturlichen information. EBM Edelsteinen und synthetischen Steinen (On the problem of gallium as proof to distinguish be- JEWELRY ARTS tween natural gemstones and synthetic mate- rials). H.-W. Schrader and U.HennJeitschrift der Antiques: alchemy of Art Nouveau. S. Birmingham, Ar- chitectural Digest, Vol. 42, No. 12, 1985, pp. Deutschen Gemmologischen Gesellschaft, Vol. 154-159. 34, No. 3/4, 1985, pp. 152- 159. The authors have proved that the presence of gallium This article is an abbreviated and generalized descrip- (Gal is not a conclusive test to distinguish the natural or tion of the exuberantly emancipated society that sup- synthetic origin of a gem. Neutron activation analysis ported Art Nouveay around the turn of the last century. (NAA)of 32 emeralds (22 natural, 10 synthetic), 18 co- However, the text merely provides a backdrop for the six rundum~'(8'natural and 10 synthetic), and 16 chryso- accompanying illustrations of exquisite French Art beryls (14 natural and 2 synthetic) yielded comparable Nouveau jewelry. The captions for these jewels provide amounts of gallium in both the natural gemstones and more information than the text, giving artist, date, ma- their synthetic counterparts. Therefore, the element Ga terials used, dimensions, and a brief historical note for should no longer be regarded as a sure sign of the natural each. Among the pieces included is the celebrated snake origin of a gem. MG bracelet and ring combination that was designed by Al- phonse Mucha and fabricated by Georges Fouquet for Touchstone testing of precious metals. W. Walchli and Sarah Bernhardt's stage premiere of "Cleopatra" in 1890. P. Vuilleumier, Aurum, No. 24, 1985, pp. 35-45. The piece incorporates gold, enamel, opals, diamonds, Touchstone testing is one of the oldest known methods and rubies in the exaggerated style that is representative of testing for precious metals. Its use is documented as of the period. The serpent motif was a popular one in this early as 600 B.C. for checking gold coins. Today, it is sensual era, when "anything that flowed, undulated, primarily used by assayers to test and hallmark articles slithered, twined, or trembled in the wind" was trans- made of noble metals. This comprehensive article lated into spectacular jewelry. Although the illustra- explains the procedures and tools needed to perform a tions are superlative, Birmingham's article only serves number of tests used to determine the alloys of silver, to whet the appetite for more information about this and yellow, white, and colored golds; distinguish be- brief, distinctive period. EBM tween solid and plated pieces; and differentiate between platinum, white gold, palladium, and steel. These tests Geneva's Mr. Christie. D. Good, Canadian Jeweller, have a wide variety of applications in the jewelry trade, Vol. 105, No. 9, 1984, pp. 27-28. ranging from evaluating antique jewelry to sorting The astonishing thing about this article is that it ap- semifinished manufactured pieces for fineness. peared at all. The author deserves high praise for liftinga Essentially, the touchstone process is a comparison corner of the veil of privacy with which Hans Nadelhof- test whereby an unknown metal is rubbed on the touch- fer, president of Christie's, Geneva, usually surrounds stone and compared with rubbings from touch needles. himself. That he should also have allowed his photo- Sometimes acids are applied to the two rubbings for graph to be published puts an otherwise routine, if not further evaluation. The tools required are a touchstone, actually dull, trade magazine interview into a special touch needles, blotting paper, and touch acids. Touch- class. stones today are usually made out of black or dark red For jewelers and gemologists who have enjoyed Dr. agate, of uniform color with no blemishes or veins, Nadelhoffer's monumental and definitive work on Car- fine-grained with a matte finish. Touch needles are tier, and who have marveled at his genius in organizing made from alloys of known composition, and the num- some of the greatest jewelry sales of this century, this

Gemological Abstracts GEMS &. GEMOLOGY Summer 1986 121 article will be of particular interest. The author briefly and elaborates on the nature of the products they carry. outlines Nadelhoffer's professional career and provides Lynn also comments on why most manufacturing jew- ample proof of the magnitude of his influence in the elers prefer to hire intermediaries, noting that salespeo- jewelry world. Only by personal acquaintance, however, ple must be outgoing, congenial, aggressive, persistent, can Nadelhoffer's innate modesty, gentility, and enor- and able to handle rejection. mous personal charm be fully understood and appreci- Some key ingredients for a successful relationship ated. NL with your rep(s) include the manufacturing jeweler's ability to think and design ahead, ready access to a Goldwork of the Iron Age in "barbarian" Europe. C. substantial amount of cash, and a real sense of commit- Elufere, Gold Bulletin, Vol. 18, No. 4, 1985, pp. ment between both parties. Many jewelers believe that 144-155. stockpiling their finished pieces is expensive and risky, Using classical references, and archeological and tech- but that it is also crucial that they are able to meet their nological evidence, the author shows how the goldwork manufacturing obligations on time. of the Celtic, Iberian, Illyrian, Thracian, Dacian, and Other sections cover how to find a rep, and what to Scythian tribes was influenced by Greek, Persian, and look for in the person who will be largely responsible for Etruscan goldwork during the Iron Age (700-100 B.C.). your commercial success. Interestingly, the majority of Gold jewelry from the preceding Bronze Age (2000-800 jewelers reported that they must really like their reps B.C.) was large and heavy. The changes in use, tech- and feel that they are genuinely interested in the lines nique, and style that developed are due, the author pos- they carry. Lynn also stresses the importance of check- tulates, to interaction via trade and/or conflict with the ing the rep's references through other artists and store Mediterranean cultures. With these changes, the use of accounts, gold acquired certain defined purposes: as a designation Novice manufacturing jewelers can benefit greatly of status, an honor to gods, and in hoarding as a store from a good rep, who can and often will help guide them of wealth. Ultimately, the latter use was manifested as through sometimes initially turbulent business maneu- coinage. vers. A good rep provides valuable feedback from the The fact that barbarian Europe had abundant marketplace, and can help a jeweler develop his or her sources of gold and other ores is documented in classical professional identity. texts which are quoted by the author. Elaborate burial The second (and shorter) part of this article deals mounds of chieftans have yielded similar examples of with jeweler/rep contracts, what they can and should adornment and ritual vessels from several different cul- cover, and how jewelers protect their freedom to repre- tural areas. These are described in detail and include sent themselves at gallery shows and sales. This section neck rings and torques, bracelets, rings, fibulae, buckles, also talks about reps' territories, the methods of com- and other ornaments, along with swords, axes, and hel- mission payment, and the length of their contracts. It mets of iron that have been decorated with sheets of also offers good advice on how to handle a rep who gold. Ceremonial cups of sheet gold and caldrons of doesn't sell or one who "loses" samnles. bronze suggesting religious rituals have also been found. As a whole, this article provides a great deal of Citing many examples, Elukre demonstrates how tech- practical information for the manufacturing jeweler niques (such as granulation and the use of solder) were who wants to expand his or her business through repre- developed, and styles (as shown by decoration motifs) sentatives. SAT and types of jewelry evolved. Much scholarly research and careful condensation A perfect match. A. DiNoto, Connoisseur, Vol. 216, No. of facts went into the preparation of this article, which 891, 1986, pp. 118-123. represents an important contribution to the literature A young designer named Kai-Yin Lo has catapulted from on this subject. The article is richly illustrated with 14 director of public relations at the Mandarin Hotel in photographs, a table showing the chronology and loca- Hong Kong to the heady realm of high-fashion jewelry tion of principal finds, and a map giving their geographic design. Her work is characterized by strong, simple de- locations. EBM signs, a sensitive use of color, and an eye-catching sym- biosis of antique and modern elements. "I draw on the Getting repped. V. S. Lynn, Metalsmith, Vol. 6, Nos. 1 vast and marvelous reserves of Chinese motifs and . . . and 2, 1985, 1986, pp. 18-23 and 34-35, respec- adapt and synthesize," she explains. tively. Kai-Yin sold her first collection to Cartier, and then Based on hours of interviews with manufacturing jew- went on to form her own company. Kai-Yin & Co. Ltd. elers and jewelry representatives (reps] in a variety of now provides jewelry and accessories to 150 retail out- markets across the country, this two-part article pre- lets on four continents, including some of the finest sents the basic considerations of a jewelerhep relation- department stores and boutiques. She features several ship. First, the author defines the various types of reps distinct lines, with items priced from $20 to $20,000.

122 Gemological Abstracts GEMS & GEMOLOGY Summer 1986 Recently, Kai-Yin became the first well-known jewelry chronological order. During the Renaissance, the bezel designer to be accepted by Chinese Arts and Crafts in of many Jewish wedding rings was set with a miniature Hong Kong, the official outlet for higher-grade goods gabled roof, symbolizing the Talmudic saying "His wife from mainland China, and is anticipating coproducing is his house." The 17th century saw the rise of the with them. gimmel, twin hoops linked together by hearts or hands. Incorporated into many of her striking designs are In the 18th century, romantic inscriptions, most often in an assortment of small objects, ranging from a tiny French, decorated the outside of many wedding rings, 18th-century Mongolian leather purse to exquisitely intertwined with cupids, hearts, or doves tying fast a carved beads and baubles of antique jade, turquoise, am- lover's knot. The venerable Queen Victoria popularized ber, or ivory. In the past few years, however, she has rings in the form of coiled serpents, representing eter- noticed that the master carvers are vanishing, and the nity. It was only after diamonds were discovered in old materials are becoming increasingly rare-and ex- South Africa in 1866, and were subsequently promoted pensive. "Gone are the days when I could buy antique by N. W. Ayer, that diamond engagement rings became turquoise by the kilo," she laments. Nevertheless, the fashion, usually paired, ironically, with simple gold Kai-Yin's versatility and the "wearable splendor" of her wedding bands. pieces seem to assure her a place in the sun for some The text is sumptuously illustrated with many fine time to come. SAT examples of wedding and betrothal rings, as well as with reproductions of medieval drawings depicting the wed- Thomas McPhee, gem carver. D. Luckow, Canadian ding rite. SAT Jeweller, Vol. 107, No. 1, 1986, pp. 36-37. Thomas McPhee, of Rare Earth Gems in Vancouver, SYNTHETICS AND SIMULANTS British Columbia, has taken the gem-carving craft by storm. Although he has only been working with stone Neue Untersuchungen an in Japan hergestellten syn- for the past two and a half years, his overwhelming thetischen Amethysten (New investigations con- success at the 1985 Tucson Gem and Mineral Show, and ducted on Japanese-made synthetic amethysts). s~bse~uehi'encouragementby Roland Naftule, past Th. Lind and K. Schmetzer, Zeitschrift der president of the American Gem Trade Association, have Deutschen Gemmologischen Gesellschaft, Vol. boosted the young Canadian carver into the limelight. 34, No. 3/4, 1985, pp. 160-164. His most -popular works include carvings of faces, In general, the distinction of natural and synthetic ame- masks, animals, and birds of "exceptional quality and thysts is determined with the conoscope (a kind of polar- artistic design." McPhee carves almost any type of gem izing microscope), a gemological microscope, and in material, although tourmaline is by far his favorite. The complicated instances by the use of infrared spectros- largely self-taught artisan is presently working on a col- copy. Characteristic features of synthetic amethysts, laborative jewelry line which will include his own carv- particularly those made in Russia, have appeared in re- ings in pendants, rings, bracelets, and brooches. Another cent gemological publications. However, the increased line featuring small carved gemstone boxes and rock amount of amethysts synthesized in Japan that are now crystal bowls is also in the works. SAT available in the trade prompted the authors to investi- gate this material in detail. The new product from Japan often contains feathers that consist of liquid-filled and JEWELRY RETAILING two-phase inclusions, sharp growth zoning parallel to one rhombohedra1 face, and twin structures. The twin- The story of love and wedding rings. D. Scarisbrick, ning is readily distinguishable from the polysynthetic Aur~zm,No. 24, 1985, pp. 46-53. lamellae twinning seen in natural amethysts. The six Scarisbrick traces the history of wedding rings from the color photographs provided with the article are useful to days of the Roman Empire to the 20th century. Around the gemologist. MG 23-79 A.D., it was customary to exchange rings at the close of a business transaction, signifying the good faith of each party. This custom came to be applied to mar- Quantitative Kathodolumineszenz-ein neues Ver- riage contracts as well; after the dowry was settled, the fahren zur Unterscheidung echter von synthetis- prospective groom placed a simple iron (orgold for nobil- chen Smaragden und Rubinen (Quantitative ity) band on the fourth finger of the left hand of his cathodoluminescence-a new process of distin- betrothed. In fact, many rings were shaped to form two guishing between natural and synthetic emerald clasped right hands, symbolizing the contractual hand- and ruby). J. Ponahlo and T. Koroschetz, shake. This design continued to be popular throughout Zeitschrift der Deutschen Gemmologischen the centuries, and can still be found on many modern Gesellschaft,Vol. 34, No. 3/4, 1985, pp. 132-142. Irish wedding rings. Recent developments in the technical aspects of manu- Several other interesting rings are also discussed in facturing synthetic stones have yielded enormous prog-

Gemological Abstracts GEMS & GEMOLOGY Summer 1986 123 ress, which in turn causes difficulties in separating natu- used in the production of the other materials are not ral from synthetic stones with standard gemological or specified. mineralogical methods. In their search for a solution to These floating zone-produced materials are all this problem, the authors report on microphotometric characterized by the presence of internal, irregular flow measurements of luminescence intensities emitted lines, which are evident in a characteristic swirled color from emeralds and rubies during bombardment with distribution. This diagnostic feature is most prominent fast-moving electrons (cathode rays). in the synthetic ruby; immersion may be required to The method, conducted on a luminoscope, is called detect it in the other materials. Also characteristic of the "quantitative cathodoluminescence" (CL).The integral synthetic ruby is rectilinear parting. Fluorescence can be photocurrent intensity of the cathodoluminescence is of diagnostic value in some cases, since both the syn- plotted against the power of excitation. The natural em- thetic orangy pink sapphires and the synthetic alexan- eralds exhibit a very small linear increase in intensity, drite glow a strong red to long-wave ultraviolet radia- whereas synthetic emeralds show a manyfold greater tion. Other gemological properties overlap with those of increase. In general, the rubies yield an exponential in- the natural materials. crease in luminescence intensity when the power of the comprehensive table summarizes the gemologi- excitation is raised. The authors compared Thai rubies calproperties of the Seiko synthetics and of their natural as natural samples with synthetic rubies by manufac- counterparts. RCK turers such as Chatham, Kashan, and Knischka. The CL intensities of the synthetics are comparatively higher Die synthetischen "Ramaura-Rubine" und ihre Erken- than those of rubies from Thailand. nungsmoglichkeiten (The synthetic Ramaura Quantitative cathodoluminescence seems to offer a ruby and its identification characteristics). W. relatively safe method of differentiating between natu- Galia, Uhren Juwelen Schmuck, Vol. 2, No. 2, ral and synthetic emeralds, as well as between Thai 1986, pp. 154-157. rubies and their man-made counterparts, especially the The author first encountered the new "Ramaura" syn- Kashan synthetic ruby. Measurements are now being thetic ruby in 1984 and introduced it to the trainees at carried out on rubies and emeralds from other sources Konigstein gemological education center in Germany. and producers as well as on sapphires and alexandrites. The production method is said to be spontaneous nucle- However, detailed results on the latter are not included ation (no seed) involving flux, with crystallization tak- in the article. The paper includes six color photographs ing place at a temperature of about 1250°Cwhich is and two diagrams to show comparative luminescence of higher than usual for flux ruby crystallizations. synthetic and natural emerald and ruby. MG The crystal form and color reported here for Ramaura synthetic rubies are identical to the details published by Kane [Gems sJ Gemology, Fall 1983).The Seiko synthetics. G. Brown, Australian Gemmologist, important gem microscope observations indicate the Vol. 15, No. 11, 1985, pp. 418-420. presence of flux residue often as lacy patterns and tri- gonal growth marks parallel to the (0001)face. The arti- Adapted from technical information supplied by Suwa cle includes 15 color photographs that show rough crys- Seikosha Co. of Japan, the article reports on the produc- tals, faceted Ramaura rubies, and various types of tion and properties of five synthetic gem materials inclusions. MG manufactured by their subsidiary, Hattori Seiko Co., Ltd. TREATMENTS The Seiko synthetic emerald is produced by a flux- growth process, reportedly using a new flux that results Oven fresh sapphires. T. Themelis, Lapidary Journal, in a purer crystal than is possible from older flux-growth Vol. 39, No. 11, 1986, pp. 49-53. methods. Gemological properties of this material are This article reports on the author's personal observa- within the ranges for other flux-grown synthetic emer- tions of heat treating sapphire in Sri Lanka. Material alds, with the exception of the reaction to ultraviolet treated included "Geuda" rough, other corundum con- radiation, which is a greenish color to both long- and taining various amounts of silk, and material previously short-wave U.V. treated unsuccessfully. After trimming to remove major Synthetic ruby, blue sapphire, orange-pink sap- inclusions, the corundum is placed in a crucible consist- phire, and alexandrite chrysoberyl are all produced by a ing of a perforated, high alumina-content brick. This is floating zone method, which is described and illus- placed in a furnace that is no more than a steel drum trated. This method of synthesis reportedly produces lined with bricks. The burner unit consists of a main crystals of uniform color and luster, with no chemical blower, a controller, and a pump. impurities and a minimum of gas bubbles. The synthetic The loaded crucible is placed in the oven and the ruby is grown in an inert atmosphere; the atmospheres temperature is then raised to about 1800° over a four-

124 Gemological Abstracts GEMS & GEMOLOGY Summer 1986 hour period. At this point, the oven is "hermetically" ward to collide with the Asian landmass beginning sealed to create a reducing atmosphere. Heating con- about 40 million years ago. This collision produced the tinues for eight to 10 hours or longer. Two or three times Himalaya orogenic belt. The northward movement of during heating the temperature is lowered and the fur- India continues at a rate of about 5 cm per year. The nace opened for a visual inspection of the corundum. resultant shortening of the crust is accompanied by ex- The temperature is then lowered over a four-hour period tensive faulting, earthquakes, and the continental uplift and the oven is allowed to cool an additional 24 hours of the Himalayas themselves, which is occurring at the before it is opened and the stones are removed. Recovery rate of up to several millimeters per year. IES of usable material is estimated at 25% of all material Editor's Note: For another general overview of the treated. Himalaya Mountains, see Geology Today, 1985, Vol. 1, There are a number of statements in this article that No. 6, pp. 169 -1 73, "The Himalayas," by B. F. Windley. must be questioned. The dimensions listed for the open- ing in the furnace ("about six feet to a side") and of the crucible (6' x6' x 4') would appear unlikely. The iron and Gold boom in Mali. C. Philippart de Foy, Europe Star, titanium color-causing agents are described as "blue Vol. 152, No. 5, 1985, 5 pp. colored atoms." The statement that pyrometers are not used "since the process is performed in a totally en- In the African nation of Mali, one of the poorest coun- closed environment" seems an unlikely explanation. tries in the world, even the smallest amount of gold is The chemical formula for ilmenite-FeTiOa-is incor- treasured. In February 1982, a woman gathering wild rectly written TiFe03. The melting temperature of plants along the banks of the Niger River discovered a quartz is given as 1825OC, whereas it should be 1610°C gold nugget caught in the plant roots. Two days later the Finally, the author also quotes the melting points of the word was out and the gold rush at Bamako had begun. elements titanium and iron when it is not the pure Today, hundreds of gold washers work the placer de- elements, but the oxides, that are involved in the reac- posits. The men dig pits with primitive tools at about 2 tion underdiscussion. R CK m a day. Once through the alluvial covering, they dig out 4, the gold-bearing layer and deliver it to the women at the surface. Here the gravel is washed in a hollowed-out gourd called a calabash. The shafts have no shoring, and MISCELLANEOUS accidents caused by the collapse of the workings are The geologic history and structure of the Himalayas. P. frequent. Although gold washing provides a living only Molnar, American Scientist, Vol. 74, No. 2, 1986, for the lucky, it provides hope for everyone. GSH pp. 144-154. The Himalayas make up the world's highest and youngest mountain belt. They are between 250 and 350 The regulation maze. E. Salomon, American fewelry km wide and extend from Afghanistan to Burma. Besides Manufacturers, Vol. 33, No. 7, 1985, pp. 20-25. containing some of the most majestic scenery on earth, This is an extremely important article for everyone in- this mountainous region has been an important source volved in jewelry manufacturing. It outlines the regula- of gemstones from antiquity through modern times. tions regarding toxic waste disposal that are being en- This article presents a general summary of the geology forced with increasing severity. The most important and geologic history of the Himalayas that would be of point that this article makes is: "You must be familiar interest to anyone who wants to know more about this with your local requirements. Ignorance is no excuse for gem-producing region. It is well illustrated with color nonc~mpliance!~'Any company that is involved in plat- photographs and color diagrams, and is written in a ing and metal finishing of any sort is required by law to readable, nontechnical style. dispose of waste properly. Congress is exerting pressure The Himalayas are of great scientific interest today on the Environmental Protection Agency to oversee the because they represent a classic "modern" orogenic belt individual state authorities, who are in turn enforcing that exhibits many features consistent with the recent regulations through the sewer officials. The author em- geologic theory of plate tectonics. According to this the- ohasizes that environmental issues can be solved effi- ory,. . blocks of continental crust have moved relative to ciently by educating ourselves to the laws that pertain, one another throughout geologic history. This move- and by exploring alternative technologies that help to ment is caused by the movement of material in the reduce waste through recycling and recovery methods. underlying mantle. Collisions of two continental blocks Charts are provided that list where to find out the laws result in the formation of mountainous orogenic belts. that are in effect as well as the dates they are effective, Recent geologic studies have suggested that the together with discharge limitations and the various Indian subcontinent, after splitting away from an earlier metal-finishing operations that must comply with these large landmass called Condwanaland, drifted north- regulations. EBM

Gemological Abstracts GEMS & GEMOLOGY Summer 1986 125 BIRTHDAY BOOK well worth reading. Mr. Green con- OF GEMS cludes with a summary of the domi- By Harold and Erica Van Pelt, 128 nant factors affecting the price of pp., illus., publ. by Van Pelt Photog- gold, the complexities of the market, BOOK and the interdependence of everyone raphers, Los Angeles, CA, 1986. USfl8.95 * in the chain, from the suppliers to the ultimate consumer. He also em- Previous editions of the Birthdav REVIEWS phasizes the important part that pol- Book of Gems have been enormously [ JeffreyM. Burbank, Editor 1 itics plays in the world spot price of successful, and this one promises to gold. This book is a must for anyone be even more so. Like its predeces- interested in investing in gold, and sors, it is filled with color photo- would be very useful to jewelers or graphs that are typically superb Van goldsmiths who are required to make Pelt productions, accompanied by United States, and Canada through intelligent decisions regarding when instructive captions that make this the markets in London, New York, and when not to buy this precious appointment book even more valu- Zurich, Hong Kong, and Singapore to metal. able. the buyers throughout the world. His The historical pieces, such as journalistic approach to the subject WAYNE C. LEICHT Kristalle Empress Marie Louise's diamond makes the information interesting- Lapna Beach, CA necklace, a pair of large diamond and easy to read, unlike the dry, mo- earrings once owned by the unfortu- notonous data normally presented in nate Marie Antoinette, and the Hope economic journals. The book is DIAMOND, RUBY, diamond, are particularly intriguing. richly annotated with footnotes, ref- EMERALD, AND The necklace containing 52 faceted erences, and a bibliography for fur- SAPPHIRE FACETS benitoites must surely rank as one of ther reading. the rarest of ornamental objects. I es- The first part of Green's book, By Gary Grelick, 56 pp., illus., pri- pecially liked the magnificent pho- "The Gold Rush Days," gives the vately published, 1985. US$5.00* tograph of a pair of remarkable ame- reader a brief historical account of The stated purpose of this publica- thyst geodes, as well as the photos of the hardship men will endure in tion is to "give the layman a working carving work done by Idar-Oberstein search of the yellow metal. Part 2 knowledge of diamonds, rubies, em- artisans (and by the Van Pelts them- deals with "The Miners" or, more eralds, and sapphires." The author selves) and the crystals and suites of specifically, the mines themselves, seeks to accomplish this by supply- cut tourmalines and bervls. which supply the world's seemingly ing information regarding optical Another nice feature about this insatiable demand for - gold. Green and physical properties, nomencla- calendar book is that it is places a special emphasis on the ture, formation, sources, and identi- perpetual-if you hid it away and did manipulations of the producers to fication of the four gemstones. Mr. not exhume it until the year 2000, it control the sources of -eold. I was Grelick also includes an explanation would still be as applicable as it is particularly interested in the au- of the four C's in reference to today. thor's views on the impact of Rus- diamonds. The subject matter is pre- JOHN SINKANKAS sian gold on the international sented in a simplified, easy-to- Earth Science Literature market, and how Russia uses its gold understand manner; however, there San Diego, CA to advantage. Part 3, "The Markets," are quite a few inaccuracies and even is just that-except for a final section more typos and grammatical errors. on gold smugglers that has all the For example, the author states that THE NEW WORLD intrigue and suspense of a first-rate "a Colombian emerald is light green OF GOLD spy novel. The reader also gets some in color. . . ."To most gemologists, a insight into why London historically beryl with a light green color would By Timothy Green, 290 pp., paper- has been, and continues to be. the not be considered emerald, so how back, publ. by Walker and Co., New focal point of the international gold could the source of the world's finest York, NY 1984 (rev.), US$12.95 * market, and why Zurich or Hong emerald owe its fame to light green The title page of this book indicates Kong might be the best place for the material? Mr. Grelick also mentions that it is "The inside story of the small investor to purchase gold. that iron is not found as an impurity mines, the markets, the politics, the This is not a book for someone in any natural emerald, and that this investorsff-a tall order for a book of looking for technical information on fact can be used as a basis for separat- only 290 pages. Fortunately, Mr. gold alloys, solders, wire sizes, and so Green has a remarkable talent for forth. But if you're interested in the giving the reader a good overall view political motivations of the pro- of the intricate and mysterious world ducers, dealers, and countries to *This book is available for purchase at of gold-extending from the mines in manipulate the price of gold to their the GIA Bookstore, 1660 Stewart Street, South Africa, Russia, Brazil, the advantage, then you'll find this book Santa Monica, CA 90404.

126 Book Reviews GEMS & GEMOLOGY Summer 1986 ing natural emerald from the non- also sets out to interpret the "strange with this impeccable book. Alto- fluorescent, iron-bearing Gilson and unprecedented characteristics" gether, it is as beautifully designed synthetic. This is simply not true. that these jewels exhibit. The intro- and executed as the jewelry it de- Iron can be an impurity in natural duction provides an overview of the scribes. emerald, which can therefore exhibit Art Nouveau style as it developed ELISE B. MISIOROWSKI the same properties (e.g., absorption internationally, putting into per- Research Librarian pattern] as the iron-doped Gilson. spective the artistic, social, and eco- GIA-Sania Monica In discussing the identification nomic forces that gave birth to the of natural sapphire, the author states Art Nouveau movement. that "the inexperienced gemologist In the late 19th century, many REVIEWS IN MINERALOGY will often find it particularly difficult artists felt dissatisfaction with the VOLUME 12: FLUID to separate a natural green sapphire dehumanizing effect that factories from a synthetic green zircon." It is and industry had on art-and on life INCLUSIONS doubtful that even an experienced in general. Their idea was to infuse BY Edwin Roedder, 644 PP., jll~zs., gemologist has seen synthetic green everyday objects with art, thereby ere- pub]. by the Mineralogical Society of zircon (or synthetic zircon of any ating a source of contentment for the America, Washington, DC, 1984. color] since this is not a material artist and user alike. This return to US$15.00* synthesized on a commercial basis. craft, which was incorporated into On the cover of his new book, Dr. This statement is confusing and every aspect of turn-of-the-~ent~ryEdwin Rocdder states that "Fluid inaccurate. life, found its ultimate expression in Inclusions is an introduction to stud- In addition to the bothersome jewelry. The designs reflected a free- ies of all types of inclusionsÑgas number of typos and grammatical er- dam of expression that was a reac- liquid, or melt-trapped in materials rors, the eight photographs of the tion to the staid and restrictive Vic- from earth and space, and of their aforementioned gemstones and their torian period. The flowing Art NOU- "application to the of captions are very disconcerting. The veau line expressed rmvement and geologic processes." Although this photos themselves are surprisingly youthful vitality, as d~~wnin a wo- description is precise, in some ways unimpressi've, as the featured stones man's billowing hair, sensuous it is an understatement. Fluid Inclu- are not particularly attractive, nor plants, and sinuous animals. Perhaps sions is the 12th volume in the Min- are they displayed well. Also, the the greatest impact on design at this eralogical Society of America's Re- captions do not identify the pictured time was the opening of trade with views in Mineralogy series. ~t is the stones in their respective orders or Japan and the importation of Ja- only single-author volume in this numbers. Although the intent of this panese art and artifacts into Europe. important series, and at 644 pages it book is clearly an honorable one-to The simplicity and naturalism of ]a- is also the longest. The book's 19 furnish the uneducated consumer ~anesedesign was adopted by the art- chapters are very well organized and with a quick and ready reference-it ists of Europe and was incorporated take the reader (in chapter 1)through falls far short of its promise. into every artistic medium, particu- the early history of fluid-inclusion DEBORAH HISS larly Jewelry. The artists borrowed study with the writings of such noted Instructor, GIA-Santa Monica not only the designs but also the researchers as Robert Boyle, Henry ideas for techniques and use of ma- Clifton Sorby, and Ferdinand Zirkel terials. Becker lucidly Puts forth to (in chapter 19)the possible future ART NOUVEAU JEWELRY these important factors and con- of inclusion studies. Interestingly, tinues by addressing each country in Roedder notes that the first mention By Vivienne Becker, 240 pp., illus., New subsequent chapters, outlining the ever in the English language of in- pzzbl. by E. P. Button, York, NY, contributions made by each to the clusions was made by Robert Boyle 1985. US$50.00 * Art Nouveau movement as a whole. in a gemological text titled "Essay This book is simply excellent. Beau- Logic governs the layout of the about the Origine and Virtues of tifully written and lavishly illus- book, which flows smoothly from in- Gems" (16721. This fact solidly ce- trated with superlative photographs, troduction to final credits with the ments the close relationship that ex- Art Nouveau Jewelry is an outstand- help of Becker's descriptive style. ists between inclusions and gemol- ingreference for anyone interested in The text is well annotated, and the ogy. jewels of this period. photographs and illustrations are well Between the historic past and In the preface, the author states captioned. Brief biographical the possible future, Dr. Roedder de- her intention to present a "broad sketches of the jewelers along with a tails the various trapping panorama" of Art Nouveau through guide to their makers' marks are nisms by which inclusions are its jewelry, as well as to explain the helpful additions, and, other than the history of its roots and rapid growth peculiar choice of a lurid reddish or- at the turn of the last century. Becker ange for the cover, I can find no fault Continued on p. 107

Book Reviews GEMS & GEMOLOGY Summer 1986 127 GEMS & GEMOLOGY is an inter- national publication of original con- tributions [not previously published in English) concerning the study of ~wggestiousr for gemstones and research in gemology and related fields. Topics covered include (but are not limited to) col- ored stones, diamonds, gem instru- ments, gem localities, gem substi- tutes (synthetics),gemstones for the Previous Studies, Methods, Results, should be considered whenever the collector, jewelry arts, and retail Discussion, Conclusion. Other heads bulk of information to be conveyed management. Manuscripts may be and subheads should be used as the in a section threatens to overwhelm submitted as: subject warrants. For general style, the text. Original Contributions-full-length see A Manual of Style (The Univer- Figures. Please have line figures articles describing previously un- sity of Chicago Press, Chicago). (graphs, charts, etc.) professionally published studies and laboratory or References. References should be drawn and photographed. High-con- field research. Such articles should used for any information that is trast, glossy, black-and-white prints be no longer than 6,000 words (24 taken directly from another publi- are preferred. double-spaced, typewritten pages) cation, to document ideas and facts Submit black-and-white photo- plus tables and illustrations. attributed to-or facts discovered graphs and photomicrographs in the Gemology in Review-comprehen- by-another writer, and to refer the final desired size if possible. sive reviews of topics in the field. A reader to other sources for adcli- Color photographs-35 mm slides maximum of 8,000 words (32 dou- tional information on a particular or 4 x 5 transparencies-are ble-spaced, typewritten pages) is subject. Please cite references in the encouraged. text by the last name of the author(s) recommended. All figure legends should be typed and the year of publication-plus Notes & New Techniques-brief double spaced on a separate page. the specific page referred to, if ap- preliminary communications of re- Where a magnification is appropri- propriate-in parentheses (e.g., Lid- cent discoveries or developments in ate and is not inserted on the photo, dicoat and Copeland, 1967, p. 10). gemology and related fields (e.g., new please include it in the legend. The references listed at the end of instruments and instrumentation the paper should be typed double techniques, gem minerals for the spaced in alphabetical order by the MANUSCRIPT SUBMISSION collector, and lapidary techniques or last name of the senior author. Please Please send three copies of each new uses for old techniques). Arti- list only those references actually manuscript (and three sets of figures cles for this section should be about cited in the text (or in the tables or and labels] as well as material for all 1,000-3,000 words (4-12 clouble- figures) sections to the Editorial Office: spaced, typewritten pages). Include the following information, Gems a) Gemology, 1660 Stewart Street, Santa Monica, CA 90404. MANUSCRIPT PREPARATION in the order given here, for each ref- erence: (a)all author names (sur- In view of U.S. copyright law, a All material, including tables, leg- names followed by initials); (b)the copyright release will be required on ends, and references, should be typed year of publication, in parentheses; all articles published in Gems a) double spaced on SVi x 11" (21 x 28 (c)for a journal, the full title of the Gemology. cm)sheets. The various components article or, for a book, the full title of No payment is made for articles of the manuscript should be pre- the book cited; and [cl) for a journal, published in Gems d Gemology. pared and arranged as follows: the full title of the journal plus vol- However, for each article the au- Title page. Page 1 should provide: ume number and inclusive page thors will receive 50 free copies of (a)the article title; (b)the full name numbers of the article cited or, for the issue in which their paper of each author with his or her affil- a book, the publisher of the book appeared. iation (the institution, city, and state and the city of publication. Sample or country where he/she works); and references are as follows: REVIEW PROCESS (c)acknowledgments. Daragh P.J., Sanders J.V. (1976) Manuscripts are examined by the Abstract. The abstract (approxi- Opals. Scientific American, Vol. Editor, one of the Associate Editors, mately 150 worcls for a feature arti- 234, pp. 84-95. and at least two reviewers. The au- cle, 75 words for a note) should state Lidclicoat R.T. Jr., Copeland L.L. thors will remain anonymous to the the purpose of the article, what was (1967)The Jewelers' Manual, 2nd reviewers. Decisions of the Editor done, and the main conclusions. ed. Gemological Institute of are final. All material accepted for Text. Papers should follow a clear America, Santa Monica, CA. publication is subject to copyeclit- outline with appropriate heads. For Tables. Tables can be very useful in ing; authors will receive galley proofs example, for a research paper, the presenting a large amount of detail for review and are held fully respon- headings might be: Introduction, in a relatively small space, and sible for the content of their articles.

128 Suggestions for Authors GEMS & GEMOLOGY Summer 1986