INDEX. 



1263 



Page. 

 Hydrargillite, chemical and physical constants of. 198, 234 



occurrence, sources, and alterations of 1235-236 



See also G-ibbsite. 



Hydration, alterations produced by. . 401 



conditions favorable to 89 



definition of ._ 304 



depth and pressure required for reversal of .. 180-181 



discussion of . .. 481-483 



examples of 179-180 



extent of, in belt of cementation 164, 165, 166, 612 



limitation of, by expansion of volume. 481 



occurrence of, in zone of katarnorphism 178 



water fixed by, amount of _■_ 161-162 



Hydration and carbonation, alterations produced 



by __ 396 



Hydration and decarbonation, alterations produced 



by 401-402 



Hydration and dechloridation, alterations produced 



by 403 



Hydration and defluoridation, alterations produced 



by 403 



Hydration and desilication, alterations produced 



by 404 



Hydration and oxidation, alterations produced by.. 404 

 Hydration and silication, alterations produced by. . 405 

 Hydration, carbonation, and dechloridation, altera- 

 tions produced by 398 



Hydration, carbonation, and desilication, altera- 

 tions produced by 398-399 



Hydration, carbonation, and desulphation, altera- 

 tions produced by 399 



Hydration, carbonation, and oxidation, discussion 



of 483-484 



Hydration, 'carbonation, and silication, alterations 



produced by _ _. 399 



Hydration, decarbonation, and dechloridation, al- 

 terations produced by.. __ 403 



Hydration, dechloridation, carbonation, and desili- 



eation, alterations produced by _ 403 



Hydration, desilication, and decarbonation, altera- 

 tions produced by _ 401 



Hydration, oxidation, and desilication, alterations 



produced by 405 



Hydration, oxidation, carbonation, and desilica- 

 tion, alterations produced by 390 



Hydrobiotite, chemical 1 and physical constants 



of. 



source and mode of formation of 339, 



340,342,370,378,397 



Hydrogen in earth's crust, amount of 981-982 



in earth's crust, percentage of _ _ 934, 936 



in sea water, percentage of __ __ 942 



occurrence and combinations of _ _ _ _ 981-983 



of volcanoes and fumaroles, sources of 492 



oxidation of, in belt of weathering 461-465 



Hydrogen sulphide, sources and importance of. 1112-1114 



Hydrolysis, increase of amount of, with increase of 



temperature 108 



importance of, possible, in metamorphism 108 



of sodium silicate, observations on ._ 67 



phenomena of. 86-87 



Hydromagnesite, chemical and physical constants 



of 198 



sources and modes of formation of 235,370,379,396 



Hydromuscovite, sources and modes of formation 



of 255,293,312,353,370 



See also Pinite. 



Page. 

 Hydroneph elite, chemical and physical constants 



of - 198,329 



occurrence and associations of. __ 331-333 



sources and modes of formation of 292, 



295,331-333,370,388,392,397,398 

 Hydrophlogopite, chemical and physical constants 



of 198 



source and modeof formation of 343,370,389,397 



Hydrosulphuric acid, oxidation of, by bacteria, for- 

 mula for reaction 468 



production of _ 468 



solubility of sulphides in .._ 1106 



Hydrosphere, percentage of known matter of globe 



formed by.. 933 



See also Ocean. 

 Hydrotalcite, source and mode of formation of... 309-370 

 Hydrous silicates, alterations and alteration prod- 

 ucts of 519 



Hygrometric water in rocks, definition of 124 



Hypersthene, alteration of, to talc, magnetite, and 



quartz, volume change incident to. . _ 633 



alterations and alteration products of 268-271, 



373,379,385,399,404,405 



chemical and physical constants of 198,267 



occurrence and associations of... 268 



sources and modes of formation of 268, 



302, 339, 342, 370, 375, 376, 379, 383, 390, 396, 401 

 Hypersthene, calcite, and quartz, alterations and 



alteration products of 379, 407 



Ice, change of water to. See Freezing. 



Idaho, South Mountain district of, ore deposits and 



gangue minerals of. _ 1056 



Idaho Springs, Colo., ore shoots near, intersecting 



fractures at __ 1227 



Iddings, J. P., Cross, Whitman, Pirsson, L. V., and 

 Washington, H. S., on mineral com- 

 position of amphioble-gabbro 632 



Igneous and crystalline rocks, analyses of . . _ 934-935 



Igneous intrusion, features of 48S-494, 646-652, 707-736 



ground-water temperature as affected by 590-591 



metamorphic effects of 42,54,716-736,1014-1017 



factors influencing, composition of intrusive 



and intruded rocks 650 



depth of intrusion 652 



groundwater 650 



length of time of intrusion 651-652 



porosity of rocks 649-650 



pressure _ 652 



size of intrusive masses 651 



temperature of intrusive 652 



minerals formed by _ 717-720 



water released by, in zone of anamorphism 662 



work of, in belt of cementation. 646-652 



Igneous processes, ores produced by 1043-1052,1233 



Igneous rocks, chemical composition of 890 



classification and nomenclature of 904-906 



effects of, in metamorphism ,_ 42 



importance of, as sources of ore deposits... 1030-1034 

 metamorphosed, and metamorphosed sedimen- 

 tary rocks, discrimination between, 



criteria for. _ 908-917 



minerals in, percentages of __ _ 937 



ore deposition as affected by _ '101 4-1017 



ore deposits in 1030-1034 



