B Babyhead: 72 Balcones fault zone: 10, 42, 45, 88 Bandera County: 45 Baringer Hill pegmatite: 80 barite: 15, 28, 31, 32, 35, 36, 38, 44, 48 barium: 45 Barrilla Mountains: 85 Baylor County: 45, 52, 98 basal cleavage: 76, 93, 94 basalt: 40, 41, 45 basement: 2, 9 Bastrop County: 64 Bell County: 69 bentonite: 51, 52 beryllium: 80 Big Bend area: 9, 42, 51, 75, 77 Big Branch Gneiss: 59 biotite: 32, 33, 34, 76 Bird mine: 90 Blanco County: 44, 58, 59, 61, 70, 83, 87, 94 black mica (_see_ biotite) blast furnace: 70, 71 blast sand: 86 bleaching clay: 51 blue copper: 53 Boerne: 18 Boling salt dome: 91 books about rocks and minerals: 24, 39, 100 brass: 52 braunite: 26, 27, 73 Brazoria County: 91 Brazos County: 98 Brazos River, Double Mountain Fork and Salt Fork of: 43 breccia: 12, 41, 81 Brewster County: 45, 46, 47, 49, 50, 57, 65, 70, 76, 77, 78, 82, 84, 85, 90 brimstone: 90 bronze: 52 Brooks County: 64 Brown, Thomas E.: vii Brown County: 45, 49 brown iron ore (_see also_ limonite): 70 Bryan Mound salt dome: 91 building sand: 85 Burnet: 56, 80, 97 Burnet County: 18, 53, 54, 55, 56, 58, 59, 60, 61, 62, 63, 70, 76, 79, 80, 81, 82, 83, 97 C calcareous sinter and tufa: 46 calcite: 7, 14, 18, 19, 20, 21, 28, 30, 31, 32, 34, 35, 36, 38, 45, 46, 49, 50, 51, 54, 56, 64, 68, 75, 86, 87, 88, 91 dog-tooth spar: 46, 47 Caldwell County: 88 caliche: 46, 47 Cambrian: 2, 3, 55, 58, 69, 86 Cameron County: 66 Capitan reef limestone: 1 Capitol building, Texas State: 62 cap-rock: 91, 92 carats: 60 carbon: 62, 63 carbonized wood: 20 carnotite: 30, 95, 97 Carrizo Mountains: 67, 83, 95 Casey, Miss Josephine: vii Cass County: 70 cassiterite: 27, 32, 47 Castile Gypsum: 91 Catahoula strata: 78, 86, 97 cave deposits: 18 caves: 18, 19, 49 Caverns of Sonora: 19 Cedar Lake: 83 Cedar Park: 70 celestite: 20, 28, 30, 35, 38, 48 cementing materials: 12, 46, 67, 70, 86 cerargyrite: 28, 29, 34, 37, 89, 90 cerium: 80 chalcedony (_see also_ agate): 16, 21, 45, 78, 81, 83, 86 chalcocite: 21, 26, 27, 52, 54, 73, 89 chalcopyrite: 26, 52, 53, 54, 60 chalk: 40, _69_ chemical elements: 7 chemical sediments: 12 chemical tests: 18, 43, 46, 47, 49, 52, 53, 54, 64, 68, 75 Cherokee County: 70 chert: 19, 40, 81, 84 chessylite: 53 china clay: 51 Chinati Mountains: 45, 57, 62, 85 Chisos Mountains: 45, 62, 85 chlorite: 93 schist: 87 chrysotile: 44, 87, 88 asbestos: 44, 87 cinnabar: 36, 49 clastic rocks: 12 clay: 40, 45, 49, 51, 70, 86, 88, 91 bentonite: 45, 51, 52 bleaching clay: 51 china clay: 51 kaolin: 51 clay minerals: 51 Clay County: 52 Clear Creek area: 63 cleavage: 17 basal: 76, 93, 94 cubic: 17, 57, 65 octahedral: 56, 57 pyramidal: 74