e, H. M., 367, 368

Chert, use for abrasives, 267, 268, 270

Chile, borax, 275, 276
bromine, 277
coal, 116
copper, 197-199, 203
iron, 155, 161, 162, 164, 171
manganese, 176
nitrates, 100, 101-104
phosphates, 105, 106
potash, 112
silver, 232
sulphur, 109-110

Chile, commercial and political control of various minerals, 64, 261

China, antimony, 247-248, 249
arsenic, 250, 251
bismuth, 252
coal, 115, 116, 127, 154
iron, 154, 160, 164, 165, 171
petroleum, 128
salt, 294
silver, 232
tin, 260
tungsten, 183, 184

China, commercial and political control of various minerals, 64

"Chloriding" for silver ores, 314

Chrome (or chromite) ores, 178-180, 307, 365-366, 398

Clarke, F. W., 13, 17, 18

Classification of mineral deposits, 27-59
of mineral lands, 309-311
of mineral materials, adjustment of scientific to commercial names,
356

Clays, 18, 85, 91-92, 398

Cle Elum, Washington, iron ores, 58

Cleavage, 26

Cleveland district, England, iron ores, 161

Clifton-Morenci district, Arizona, copper ores, 38, 198

Climate, as a factor in exploration, 315
effect of in formation of bauxites, 246

Clinton iron ores, 9, 52-53, 163, 166-167, 218, 313, 317

Coal, conservation of, 365, 366-382
European international situation, 116-117, 386, 387, 393, 400-403
general economic and geologic features, 56, 115-127, 309, 397
reserves, 116, 360-361, 366-367

Cobalt district, Ontario, arsenic, 251
cobalt, 255
silver ores, 232, 234-235, 308, 316
use of coefficient to estimate future output, 322

Cobalt ores, 254-255, 398

Coeur d'Alene district, Idaho, lead-silver ores, 39, 45, 211, 212-213,
216, 234

Coke, 118-119

Colloids, content of in clays, 92

Colombia, coal, 116
emeralds, 289, 293
gold, 222
platinum, 238

Colombia, commercial and political control of various minerals, 64

"Colorado," 313

Colorado, arsenic, 250
asphalt and bitumen, 152
bismuth, 253
coal, 117
fluorspar, 194
gold, 222, 230
graphite, 281
lead, 211, 212
molybdenum, 186
oil shales, 150
petroleum, 133
silver, 234
tungsten, 183, 184
turquoise, 293
uranium and radium, 264-265, 266
vanadium, 187-188
zinc, 216, 219-220

Commercial and political control of mineral resou