David Turner, The University of British Columbia, CanadaLee A. Groat, The University of British Columbia, Canada

• Preface xiAcknowledgements xiiiPart I Developing Base Knowledge 11 Minerals and Mineralogy 31.1 Minerals and Rocks 31.2 What is a Gemstone? 31.3 Atoms, Elements, and Bonding 41.3.1 Protons, Neutrons, and Electrons 41.3.2 Atomic Mass 51.3.3 Atomic Structure, Electrical Charges, and Ions 51.3.4 Elements 61.3.5 Element Groups 61.3.6 Elemental Abundance in the Earth’s Crust 71.3.7 Compounds and Mixtures 81.3.8 Chemical Bonds 81.4 Physical Properties of Minerals 9References 112 Basics of Rocks and Geology 132.1 Earth System Science 132.2 The Earth’s Structure and Plate Tectonics 132.3 General Rock Types and the Rock Cycle 192.4 Metasomatism and Hydrothermal Fluids 232.5 Geological Structures 242.6 Important Rock Types for Gemstone Deposits 242.7 Weathering, Sedimentation, and Secondary Gem Deposits 26References 283 Intermediate Mineralogy 293.1 Structure and Chemistry of Minerals 293.1.1 Crystallography and Symmetry 293.1.2 Mineral Classes 323.1.3 Mineral Formulae 323.1.4 Element Substitutions 333.2 Light 343.2.1 Reflection and Refraction 343.2.2 Illumination 393.2.3 Dispersion 413.2.4 Optic Class 423.2.5 Color in Minerals 433.2.6 Pleochroism 443.2.7 Transparency 46References 474 Concepts of Gemmology and Tools 494.1 Concepts of Gemmology 494.1.1 Gemmological Properties for Testing, Faceting, and Treatments 494.2 Tools 514.2.1 Collecting and Field Tools 514.2.2 Gemmological Tools 524.2.3 Advanced Tools 57References 60Part II Gemstones and Their Origins 635 Diamond 655.1 Introduction 655.2 Basic Qualities of Diamond 675.2.1 Crystal Structure 685.2.2 Crystal Chemistry and Type Classification of Diamond 695.2.3 Diamond Crystal Forms 715.2.4 Colored Diamonds 745.3 Common Diamond Treatments 765.4 Synthetic Diamond 795.5 Geology of Diamond and Kimberlite 795.5.1 Diamond Growth 815.5.2 Kimberlite Volcanoes 825.5.3 Lamproite 835.6 Global Distribution and Production of Diamond 845.7 Diamonds from Canada 925.8 The 4 Cs 955.8.1 Cut 955.8.2 Clarity 955.8.3 Color 965.8.4 Carat 985.9 Diamond Shapes 985.10 Diamond Valuation 995.11 Kimberley Process: A 5th C? 100References 1006 Corundum 1036.1 Introduction 1036.2 Basic Qualities of Corundum 1046.2.1 Chemistry and Crystal Structure of Corundum 1046.2.2 Corundum Crystal Forms 1046.2.3 Colors of Corundum 1046.3 Faceted Gem Corundum 1076.4 Corundum Valuation 1076.5 Corundum Treatments, Synthetics, and Imitations 1106.6 Geology of Gem Corundum: Three Main Genetic Models 1136.6.1 Metamorphic Corundum in Silica-Deficient Gneisses, Mafic-Ultramafic Rocks and Marbles 1146.6.2 Xenocrysts in Alkali Basalts and Lamprophyres 1186.6.3 Secondary Accumulation in Placers 1206.7 Rarity of Gem Corundum 1246.8 Global Distribution and Production of Corundum 124References 1277 Beryl 1317.1 Introduction 1317.2 Basic Qualities of Beryl 1327.2.1 Chemistry and Crystal Structure of Beryl 1327.2.2 Colors of Beryl and Gem Varieties 1347.3 Beryl Valuation 1387.4 Common Treatments, Synthetics, and Imitations 1407.5 Geology of Gem Beryl: Three Main Genetic Models 1417.5.1 Pegmatitic 1417.5.2 Magmatic 1417.5.3 Metamorphic 1467.6 Large Beryl Crystals 1497.7 Global Distribution of Beryl 149References 1508 Pegmatites 1538.1 Introduction 1538.2 Pegmatite Mineralogy 1538.3 Pegmatite Genesis 1548.4 Geochemical Families of Pegmatites 1558.5 Pegmatite Morphology 1578.6 Corrosion 1618.7 Rarity of Gem-Bearing Pegmatites 1628.8 Tourmaline 1628.8.1 Introduction and Basic Qualities of Tourmaline 1628.8.2 Chemistry and Crystal Structure of Tourmaline 1658.8.3 Colors and Gem Varieties of Tourmaline 1668.8.4 Tourmaline Recognition, Value and Treatments 1688.9 Spodumene 1728.9.1 Introduction and Basic Qualities of Spodumene 1728.9.2 Colors and Gem Varieties of Spodumene 1738.9.3 Spodumene Recognition, Value, and Treatments 1738.10 Topaz 1758.10.1 Introduction and Basic Qualities of Topaz 1758.10.2 Geology of Gem Topaz 1768.10.3 Colors and Gem Varieties of Topaz 1798.10.4 Topaz Recognition, Value, and Treatments 181References 1819 Chrysoberyl 1859.1 Introduction and Basic Qualities of Chrysoberyl 1859.2 Geology of Gem Chrysoberyl 185References 18910 Spinel 19110.1 Introduction and Basic Qualities of Spinel 19110.2 Geology of Gem Spinel 192References 19511 Tanzanite 19711.1 Introduction and Basic Qualities of Tanzanite 19711.2 Geology of Tanzanite 197References 20012 The Garnet Group 20112.1 Introduction and Basic Qualities of the Garnet Group 20112.2 Geology of Gem Garnet 201References 20713 Jade: Jadeite and Nephrite 20913.1 Introduction and Basic Qualities of Jade 20913.2 Geology of Jade 209References 21714 Quartz and Silica Gems 21914.1 Introduction and Basic Qualities of Quartz and Silica Gem Varieties 21914.2 Quartz 21914.3 Amethyst 22014.4 Agate 22114.5 Opal 222References 22815 Other Gems 23115.1 Olivine 23115.1.1 Introduction and Basic Qualities of Olivine 23115.1.2 Geology of Gem Peridot 23115.2 Turquoise 23615.2.1 Introduction and Basic Qualities of Turquoise 23615.2.2 Geology of Turquoise 23715.3 Lapis Lazuli 23815.3.1 Introduction and Basic Qualities of Lapis Lazuli 23815.3.2 Geology of Lapis Lazuli 23815.4 Zircon 24315.4.1 Introduction and Basic Qualities of Zircon 24315.4.2 Geology of Gem Zircon 244References 24716 Organic Gems 25116.1 Amber 25116.2 Ammolite 251References 257Index 259