Labrador, 16, 88, 91 " hornblende, see hypersthene Labradorite, see Labrador Labrador spar, see Labrador Lake George diamond, see rock-crystal Lapis lazuli, 17, 93, 124 Lava, see obsidian Light-green sapphire, see Oriental aquamarine Love arrows, see cairngorm Lustre, 17 Magnetism, 30 Malachite, 17, 127 Mica, 11 Mineral turquois, 61, 62 Mocha agate, 120 Moonstone, 17, 38, 89, 91, 109, 112 Moss agate, 120 Mother of emerald, see prase Natrolite, 29 Needle-stone, see cairngorm Nicolo, 124 Obsidian, 10, 16, 125 Occidental cat’s-eye, see quartz cat’s-eye " diamond, see rock-crystal " topaz, see yellow quartz " turquois, 62 Odontolite, 17, 62 Œil de bœuf, see Labrador Oligoclase, see sunstone Olivine, 17, 18, 53, 78, 84 Onyx, 8, 106, 107, 113, 120, 124 Opal, 8, 9, 10, 16, 17, 18, 30, 69, 100, 102, 107 " common, see opal " fire, " " " noble, " " Opaline felspar, see Labrador Oriental amethyst, 39, 44 " aquamarine, 39, 44 " chrysolite, 39, 44; see also chrysoberyl " emerald, 39, 44, 51 " hyacinth, 39, 44 " opal, see opal " topaz, 39, 44, 87 " turquois, 61 Orthoclase, 29, 87 Orthose, see moonstone Ox-eye, see Labrador Pearl, 71 " baroque, 74 " black, 73, 124 " bouton, 74 " pink, 77 Pebble diamond, see rock-crystal Peridot, 16, 78 Persian turquois, 62 Phenacite, 101 Phosphorescence, 31 Plasma, 113, 118 Pleiochroism, 14 Pleonast, 47 Polarization of light, 13 Polishing, 32 Prase, 17, 113, 117, 118 Precious schorl, see tourmaline Purple sapphire, see Oriental amethyst Pyrope, 30, 80, 82 Quartz, 9, 16, 20, 22, 42, 50, 106, 123 " cat’s-eye, see cat’s-eye quartz Rainbow agate, 119 " quartz, 112 Reconstructed rubies, 43 " turquois, 64 Red quartz, see quartz " sapphire, see ruby Refraction, 12 Rhinestone, see rock-crystal Ribbon agate, 119 Rock-crystal, 17, 38, 91, 109, 112 " salt, 11, 19 Rose quartz, 17, 113 Rose topaz, see topaz Royal agate, see obsidian Rubellite, 64, 65 Rubicelle, 48 Ruby, 14, 15, 16, 17, 18, 21, 26, 32, 37, 39, 40, 53, 64, 107 Ruby, cat’s-eye, 39, 46 " spinel, see spinel