Gem Testing

This unusual work is a complete treatise on the identification of precious stones that is thoroughly recommended for inclusion on the jeweller or antiquarian's bookshelf. Contents Include: Preface; How to Use The Book; Refractive Index and its Measurement; Double Refraction and How to Detect it; Colour, Colour Filters and the Dichroscope; Specific Gravity and How to Measure It; Detection of Synthetic and Imitation Stones; The Use of the Microscope; The Identification of Diamond; The Identification of Ruby; The Identification of Sapphire; The Identification of Emerald; Aquamarine and Alexandrite; The Identification of Zircon; The Identification of Topaz; The Identification of Pink, Mauve, etc. Stones; The Identification of Brown and Orange Stones; Quartz, Opal, and Garnets; Tourmaline, Peridot, and Spinel; Identification of Translucent and Opaque Stones; Amber, Tortoiseshell, Coral, and Jet; Pearls: Real, Cultured, and Imitation; Appendix: Glossary, Alphabetical Summary of Gem Species, Crystal Systems, Bibliography, Specific Gravity and Refractive Index Tables; Names and Addresses of Recommended Suppliers; and an Index.