INDEX TO PART IV. 
Scorodite, 
Sericite, . 
Serpentine, 
Siderite, . 
Sienite, 
Silver, F 
‘mines, . 
Silesian gabbros, 
Slate, 
Slaty cleavage, 
Smoky quartz, 
Soapstone, . 
Softening of pebbles in ‘fragmental 
rocks, . F ‘ . . i 
Spessartite, r . : F 
Sphaerosiderite, . ‘ i ‘ 
Sphalerite, - 
Sphene, . 
Spinel, 
Spodumene, 
Staurolite, . 2 
es mica schist, 
Steatite, . é 
Stibnite, 
Stinkstone, 
Stratification of gneiss, 
Strike figures on mica, 
Structural ae in eruptive 
rocks, : : 3 
Sulphur (native), 
Sulphur springs, 
Sunapee granite, 
Surface deposits, 
Syenite, see Sienite. 
Talc, z 
1 ae at which granites crys- 
ze 
Tetragonal crystals, optical proper- 
ties of ‘ 
Tetrahedrite, . 
Page. 
Thin sections, examination of 
es preparation of . 
Tin stone, e ‘ 
Titanic iron, 
Titanic iron, decomposition of. 
Titanium in iron ores, 
Titanite, ; 
Tourmaline, 
Tourmalines in mica, 
Tourmaline in quartz, 
Trachyte, . 
Tremolite, 
Triclinic crystals, optical properties of 
Triphylite, 
Tripolite, 
Troy granite, . : . : 
Twinning of feldspars, ‘ 5 ‘ 
Uralite, 
Uranium in molybdite, 
Urthonschiefer, 
57> 
Variegated copper ore, 
Veinstones, granitic 
Vesuvianite, 
Viridite, . 
Wad, 
Water, 
Wavellite, 
Wavy gneiss, . : 
Whitefield granite, - 
White iron pyrites, . 
Wolframite, 5 
Young eruptive rocks, 
Zinc blende, 
Zircon, 
Zoisite, 
16 
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