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Precious Stones Arthur Herbert L'-RARY UNIVERSITY OF CALIFORNIA DICHROISM AND SPECTRA OF PRECIOUS STONES SAPPHIRE RUBY EMERALD PERIDOT BROWN TOURMALINE BROWN TOURMALINE ANDALUSITE ALEXANDRITE ALMANDINE GARNET a B C D E b ZIRCON a B c D BOARD OF EDUCATION, SOUTH KENSINGTON, VICTORIA AND ALBERT MUSEUM. PRECIOUS STONES CONSIDERED IN THEIR SCIENTIFIC AND ARTISTIC RELATIONS WITH A CATALOGUE OF THE TOWNSHEND COLLECTION BY A. H. CHURCH, F.R.S.. M.A., D.Sc., F.S.A., Professov of Chemistry in the Royal Academy of Arts in London. NEW EDITION. LONDON : PRINTED FOR HIS MAJESTY'S STATIONERY OFFICE, BY WYMAN & SONS, LIMITED, FETTER LANE, E.C. 1905. Price Is. 6d. ; in Cloth, 2s. 3d. At Museum 1/6 EARTH SCIENCES t'BRARY CONTENTS. Page PREFACE ... v PREFACE TO FIRST EDITION . viii BIBLIOGRAPHICAL NOTES . CHAPTER I. DEFINITION OF PRECIOUS STONES . CHAPTER II. PROPERTIES AND DISCRIMINATION OF PRECIOUS STONES. CHAPTER III. 25 CUTTING AND FASHIONING PRECIOUS STONES . CHAPTER IV. ARTISTIC EMPLOYMENT OF PRECIOUS STONES CHAPTER V. ARTIFICIAL FORMATION OF PRECIOUS STONES ... .48 CHAPTER VI. IMITATIONS OF PRECIOUS STONES . .51 8445. 1000 Wt. 29306. 5/05. Wy. & S. 3407r a iv PRECIOUS STONES. CHAPTER VII. Page - DESCRIPTIONS OF PRECIOUS STONES . , .54 and 61 67 Tur- Diamond, 54 ; Corundum, Sapphire Ruby, ; Spinel, ; 75 78 ; 85 ; quoise, 70 ; Topaz, 72 ; Tourmaline, ; Garnet, Peridot, 90 91 92 Beryl and Emerald, 87 ; Chrysoberyl, ; Phenakite, ; Euclase, ; 96 96 Zircon, 92 ; Spodumene,'96 ; Hiddenite, ; Kunzite, ; Opal, 97 ; 102 lolite 103 104 Labrador- Quartz, 99 ; lapis-lazuli, ; ; Crocidolite, ; 105 106 106 106 ite, 105 ; Moonstone, ; Sunstone, ; Obsidian, ; Epidote, ; 108 Axinite, 107 ; Sphene, 107 ; Cossiterite, 107 ; Diopside, ; Apophyllite, 108; Andalusite, 109; Jade and Jadeite, 110; Pyrites, 111; Haematite, 112 ; Amber, 112 ; Jet, 113; Malachite, 113; 114 Lumachella, 114; Pearl, ; Coral, 117. THE TOWNSHEND COLLECTION OF PRECIOUS STONES . .119 CATALOGUE OF THE TOWNSHEND COLLECTION 122 INDEX 133 ILLUSTRATIONS. FIGURES 1 to 11 . ... Coloured Frontispiece. 12 FIGURES to 20 ..." . pages 26 to 30 SPECIMENS IN THE : TOWNSHEND COLLECTION pages 122 to 125 1 to Plate I Figures 20, ... facing page 122 "^ Figures 21 to 29, Plate II .. ..... 123 30 to Plate III . Figures 42, . 124 Figures 43 to 50, Plate IV .. 125 PREFACE. " " Since 1882, when the Handbook of Precious Stones was published, the volume has been several times reprinted from stereotype plates. Occasionally a few alterations and corrections were made in the text, but no opportunity occurred to improve the arrangement of the work or to add fresh material. The present issue, however, represents a thoroughly revised edition. A large number of paragraphs have been wholly rewritten, while so many additions have been made to the accounts given of the different kinds of precious stones and other beauti- ful minerals that the 112 pages of the original handbook have been increased to 140. Among the minerals which have now received fuller treatment may be named diamond, sapphire and ruby, and the different varieties of garnet and of zircon. But readers who desire to make themselves more intimately acquainted with the optical properties, the crystal-forms and intimate structure, the modes of occurrence and formation and the chemical composition and constitution of precious stones, will find it necessary to turn to works in which full details of these subjects are given. In this connection may be named the treatises of Dana, of Professor Lewis of Cambridge, Professor Maskelyne and Professor Miers, for in the pages of the present handbook only such scientific considerations find place as can be easily grasped, and which, at the same time, help to explain the beauty of precious stones and afford methods of identifying the different kinds. The chief localities where precious stones are found have leen named in Chapter VII. under the headings of the several species and varieties. But this subject cannot be adequately discussed without having recourse vi PRECIOUS STONES. could be to maps, both geographical and geological, to which no space allotted in an elementary handbook. But there is one rich district which seems to require special notice here in order to remove what seems handbook to be a prevalent misconception. In the body of the present in frequent references are made to the occurrence of many gem-stones Ceylon. The search for these beautiful minerals and the traffic in them the has, in fact, been going on in that island for ages, while plumbago and mica industries are affairs of to-day. Yet it is strange that the im- portance of the Ceylon trade in precious stones remains unrecognised not only in newspaper correspondence but in official documents and " in standard looks. One meets with such a statement as this Plum- " our mineral and The bago is, practically, only export" ; this, yield of gems in this island is not large, the total value of the annual pro- duction being said to be no more than 10,000." A glance at the true figures suffices to demonstrate the incorrectness of such statements. The value of plumbago exported from Ceylon in 1903 amounted to 119,316. Now the value of the gems exported in an average recent year by a single Colombo merchant was 30,000, while there are a score of other Ceylon gem merchants who together export no less than 200,000 worth annually. With casual sales to visitors to the island and to travelling dealers, a moderate estimate of the annual export of gems from Ceylon will be 300,000. The variety of kinds found is large, sapphires, spinels, alexandrites, chrysoberyls, beryls, topazes, catseyes, tourmalines, zircons, garnets and moonstones being the chief : diamonds, emeralds and turquoises do not occur, while pearls belong to a different category, being organic products. But it must be allowed that the precious stone industry constitutes now, as it has done for many centuries, an important feature in the resources of the island. In concluding these prefatory notes I have much pleasure in acknow- ledging the help of Dr. C. A . MacMunn, to whose skill in spectroscopy many scientists are largely indebted. He drew for me the absorption- spectra of almandine and of zircon, reproduced in the coloured frontis- piece. Although more exact in details, these drawings do not, I am glad - . , '; PREFACE. vii to say, present any obvious differences from the corresponding figures in the plate issued in 1882 with the first edition of this handbook. But they do show a marked superiority over the spectra figured in subsequent issues. The nine upper figures in the Frontispiece show the twin colours of certain precious stones, figs, i to 6 representing the hues as seen in the dichroiscope. A.H.C. KEW GARDENS, February, 1905. PREFACE. (To THE FIRST EDITION). A revised Catalogue of the Townshend Collection of Precious Stones in the South Kensington Museum originated this Handbook, in which an attempt has been made to associate, if not to combine, the scientific with the artistic study of precious stones. It has been necessary to confine this work within somewhat narrow limits, and hence to omit much which might fairly find a place in a comprehensive treatise on the subject. The writer, however, trusts that what is here offered for the consideration of students and amateurs may increase the intelligent appreciation of precious stones, and further their more judicious treatment in jewellery. Notwithstanding the exquisite skill of a few modern artist-workmen, it must be affirmed that there is room for improvement in the ordinary productions of jewellers' shops, with., respect to knowledge, taste, and finish. Chiefly in fault, however, are the purchasing public, who still tolerate the horseshoes, anchors, and clumsy cables of a debased time, and are not quick to appreciate refine- ment and originality in the selection and artistic mounting of precious stones. So a few words about these beautiful materials their nature variety, and employment -may prove of wider service than a mere descriptive catalogue of the specimens belonging to the South Kensing- ton Museum. A. H. C. KEW, Nov., 1882. BIBLIOGRAPHICAL NOTES. The following books and papers on precious stones and on related topics may be consulted, especially for such technological, historical, and archaeological details as do not fall within the scope of the present work. " MDME.-DE BARRERA. Gems and Jewels." London : Bent- ley - - 1860 " MAX BAUER. Edelsteinkunde," pp. xvi. and 712. Leip- - - zig : Tauchnitz 1896 " " MAX BAUER and L. J. SPENCER. Precious Stones, pp. - - XVI. and 627. London : C. Griffin and Co. 1904 " SIR G. C. M. BIRDWOOD. Industrial Arts of India." Vol. - - ii. pp. 17-32. London : Chapman and Hall 1881 " - - E. BOUTAN. Le Diamant," pp. 325. Paris : Dunod 1886 " " A. H. CHURCH. Physical Properties of Precious Stones. Proc. of the Geological Association, vol. v., No. 7 - - 1878 " " A. H. CHURCH. Precious and Curious Stones," Spectator," July gth - - 1870 " " A. H. CHURCH. Discrimination of Precious Stones. Journal of the Society of Arts, vol. xxix, pp. 440-446, April 8th - 1881 " L. DIEULAFAIT. Diamants et Pierres Precieuses." Paris : Hachette - 1871 '* " C. DOELTER. Edelsteinkunde, pp. viii and 260. Leipzig ; Veit 1893 2 PRECIOUS STONES. with these gems, there are doubtless several hard and beauti- ful stones which are found in less abundance, but which remain to less costly because in less demand. Yet there is something be said in favour of the high position commonly given to the diamond, the ruby, the emerald, the sapphire, and we may add and the pearl and the opal : they all possess a very conspicuous obvious beauty. By brilliancy and colour they force them- the selves upon our attention, while the spinel, the jargoon, and tourmaline generally need to be studied, to be looked into, that their merits may be discovered. But the argument that beautiful stones ought not to be employed in the higher kinds of bijouterie unless they are costly is an unworthy one.
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