Produced by The Online Distributed Proofreading Team at http://www.pgdp.net. (This file was produced from images generously made available by The Internet Archive/American Libraries.) THE CHEMISTRY, PROPERTIES AND TESTS OF PRECIOUS STONES * * * * * BY THE SAME AUTHOR THE STOLEN PLANET. (2nd edition.) 3s. 6d. THROUGH THE SUN IN AN AIRSHIP. 6s. THE IMMORTAL LIGHT. (2nd edition.) 6s. C. GRIFFIN AND CO., LTD. THE AUTOBIOGRAPHY OF A PICTURE. (2nd edition.) 3s. 6d. THIS WORKADAY WORLD. (In the Press.) HENRY J. DRANE. PEPPER'S BOY'S PLAYBOOK OF SCIENCE. (New edition.) Now in Press, revised, re-written and re-illustrated by DR. JOHN MASTIN. GEORGE ROUTLEDGE AND SONS, LTD. ETC. ETC. * * * * * THE CHEMISTRY, PROPERTIES AND TESTS OF PRECIOUS STONES. BY JOHN MASTIN, M.A. D.SC. PH.D. LITT.D. F.S A.SCOT. F.L.S. F.C.S. F.R.A.S. F.R.M.S. R.B.A. _Author of "Parasites of Insects," "The True Analysis of Milk," "Plate-Culture and Staining of Amoebae," etc., etc._ _London_ E. & F. N. SPON, LIMITED, 57 HAYMARKET _NEW YORK_ SPON & CHAMBERLAIN, 123 LIBERTY STREET 1911 Transcriber's note: For Text: A word surrounded by a cedilla such as ~this~ signifies that the word is bolded in the text. A word surrounded by underscores like _this_ signifies the word is italics in the text. The italic and bold markup for single italized letters or "foreign" abbreviations are deleted for easier reading. For numbers and equations: Parentheses have been added to clarify fractions. Underscores before bracketed numbers in equations denote a subscript. CONTENTS CHAPTER PAGE I INTRODUCTORY 1 II THE ORIGIN OF PRECIOUS STONES 7 III PHYSICAL PROPERTIES--(A) CRYSTALLINE STRUCTURE 13 IV " " (B) CLEAVAGE 19 V " " (C) LIGHT 26 VI " " (D) COLOUR 32 VII " " (E) HARDNESS 39 VIII " " (F) SPECIFIC GRAVITY 45 IX " " (G) HEAT 52 X " " (H) MAGNETIC AND ELECTRIC INFLUENCES 57 XI THE CUTTING OF PRECIOUS STONES 62 XII IMITATIONS, AND SOME OF THE TESTS OF PRECIOUS STONES 70 XIII VARIOUS PRECIOUS STONES 80 XIV " " " (_continued_) 88 XV " " " " 98 PREFACE