Bituminous coal, 27 localities, 27 region, 14 Blende, 27, 28 localities, 28 value, 28 Blowpipe, 17 Bog iron ore, 29 localities, 29 value, 29 Boring, 83 Brazil, diamonds in, 84 Bristol stones, 114 Brittle silver ore, 30 localities, 30 value, 30 Brown coal, 30 localities, 30 value, 30 Brown Hematite or Limonite, 56, 57 Calamine, 31 localities, 31 value, 31 California diamonds, 114 discovery of gold in, 127-133 Cannel coal, 31, 32 localities, 32 value, 32 Cape May diamonds, 114 Carbonated or gas spring, 106, 107 Carnelian, 32 false, how made, 117 localities, 32 value, 32 Celestine, 32, 33 localities, 33 value, 33 Cerussite, 33 and Galena, reduction of, 103 localities, 33 value, 33 Chalybeate or iron springs, 107, 108 Chromic iron, 34 localities, 34 value, 34 Cinabar, 34, 35 localities, 35 value, 35 Clear Creek, Cal., gold in, 132 Coal, anthracite, 22 bituminous, 27 brown, 30 cannel, 31, 32 Cobalt pyrites, 35 localities, 33 value, 35 Coloma, Cal., discovery of gold there, 127 Colorado silver lodes, 89 Colors, distinction of minerals by, 12 Comstock Lode, 135-137 gold and silver produced from, 136, 137 Connecticut river valley, 14 Copper, 36 glauce, 36 localities, 36 value, 36 gray copper ore, assaying, 101 localities, 36 nickel, 37 localities, 37 value, 37 ore, assay of, 100-102 gray, 51 red, 65 red, assaying, 101 variegated, 78 ores, test for silver, 99 testing, 100-102 silver in, 101 percentage of in ores, which will pay, 101 pyrites, 37, 38, 90 localities, 38 smelting, 101 value, 38 searching for, 90 seldom in new formations, 90 silicate of, 70 smelting, 101 value, 36 where found, 14, 90 Corals, false, how made, 124 Descriptive list of useful minerals, 20-80 Diamond, 41 estimation of the value of, 86 imperfections of, 86 localities, 41 value, 41 Diamonds, characteristics of, 85, 86 colors of, 83 finest, 84 in Brazil, 84 in their native state, 83 mode of discovering in Brazil, 84 prospecting for, 83-87 where found, 87 Directions for determining specimens by the key, 15-19 Discovery of silver in Nevada, 134-137 Effervescence in minerals, 12 Eliason, Mr., 133 Emerald, false, how made, 116 to test, 118 Emery, 41, 42 localities, 42 value, 42 Epsom springs, 109, 110 False amethyst, how made, 117 carnelian, how made, 117 corals, how made, 124 False emerald, how made, 116 opal, how made, 117 pearls, how made, 124 ruby, how made, 116 sapphire, how made, 116 topaz, how made, 116 Feather river, Cal., gold in, 132 Fluor spar, 42 localities, 42 value, 42 Franklinite, 43 localities, 43 value, 43 Galena, 43, 44 and Cerussite, reduction of, 103 localities, 44 purest specimens poorest in silver, 91 value, 43 Garnet, 44, 45 localities, 45 the heaviest of gems, 118 to test, 118 value, 45