Garnets (A) iron-alumina (called also almandine and precious or oriental garnet), 101 sub-variety, common garnet, 101 (B) lime-iron, 101 sub-variety aplome, 101 melanite, 101 pyreneite, 101 topazolite, 101 (C) lime-chrome, 101, 102 sub-variety uwarowite, 101, 102 (D) lime-alumina, 102 sub-variety cinnamon stone, 102 romanzovite, 102 succinite, 102 (E) magnesia-alumina, 102, 103 sub-variety carbuncle, or anthrax, 102, 103 noble, 103 pyrope, 102 (F) manganese-alumina, 103 sub-variety spessartine, or spessartite, 103 Girdle portion of a stone, 66 Glimmering, in lustre, definition of, 29 Glinting, or glistening in lustre, definition of, 29 _Goutte de suif_-cut stones, 65 Great Mogul diamond, 64 Green stones, list of, 78 Groups of crystals (see "Crystals") Hardness, physical properties of, 39 table of, 39, 40, 41 Heat indexes, 54 physical properties of, 52 Hollow-cabochon, 65 Hyacinth, ordinary (a form of zircon), 85, 98 oriental, 85 Hyalite (opal), 35 Hydrophane (opal), 35 Imitations and tests of precious stones, 70 Indigo sapphires, 86 Ink sapphires, 85 Iridescence, and cause of, 37, 38 Iron-alumina garnets, 101 Jacinth, oriental, 85 Jarcon, or jargoon, 98 Koh-i-nur, 64 Lapis-lazuli, 103 Light, physical properties of, 26 Lime-alumina garnets, 102 cinnamon stone, 102 romanzovite, 102 succinite, 102 Lime-chrome garnets, 101, 102 uwarowite, 101, 102 Lime-iron garnets, 101 aplome, 101 pyreneite, 101 topazolite, 101 List of stones according to colour, 75-79 hardness, 39-41 specific gravity, 48-50 Lustre, 26, 28 Lustreless, definition of, 29 Lynx-eye stones, 87 Magnesia-alumina garnets, 102, 103 carbuncle, or anthrax, 102 noble, 103 pyrope, 102 Magnetic and electric influences, 57-61 Malachite, 11 Manganese-alumina garnets, 103 spessartine, or spessartite, 103 Masculine stones, 85 Melanite, 101 Menilite (opal), 36 Metallic-lustre stones, 28, 29 Mohs's table of hardness, 39-41 Noble garnet, 103 or precious opal, 35 Non-diaphanous stones, 28 Odontolite, 106 Olivine corundum (see "Chrysolite"), 85 Opal, 11 varieties of, 35, 36 Opalescence (not to be confused with "Change of Colour" and "Play of Colour," which see; see also "Fire"), 36, 37 Oriental amethyst, 85 cat's eye (see "Cat's eye") emerald, 85 garnet, 101 topaz, 85 Origin of precious stones, 7 Paste, or strass, for imitation stones, composition of, 71 Pavilion portion of cut stones, 66 Pearly-lustre stones, 28, 29 Peridot (see "Noble Chrysolite"), 85 Pink-coloured stones, list of (see also Red), 77 Pinked topaz, 92 Phosphorescence, 26, 30 Physical properties:-- A.--Crystalline structure, 13 B.--Cleavage, 19 C.--Light, 26 D.--Colour, 32 E.--Hardness, 39 F.--Specific gravity, 45 G.--Heat, 52 H.--Magnetic and electric influences, 57