Benitoite, 10, 55 Beryl, 102 Blomstrandine, 10, ~68~ Blomstrandite, 10, 71 Bodenite, 11, 42, 45 Bragite, 63 Brasilite, 76 Britholite, 11, 51 Bröggerite, 11, 73 Brookite, 11, ~79~ Bucklandite, 42 Calciothorite, 11, 49 Calcite, 2, 38 Cappelenite, 11, 51 Carbides of rare earth group, ~120~ Carbonates of rare earth group, ~130~ Caryocerite, 12, 51 Cassiopeium, 205 Cassiterite, 3, 45, 46, 77 Castelnaudite, 12, 88 Cataplejite, 12, 51 Cathode luminescence, ~151~ Celtium, ~207~ Ceria, 111, 117, 118, ~161~ Ceric compounds, ~160~ Cerite, 1, ~30~ Cerium, atomic weight of, ~164~ compounds, applications of, ~317~ detection of, ~165~ estimation of, ~166~ group, history of, ~168~ separation of, ~169~ intermediate oxide of, 162 metallic, ~115~ nitrate, extraction from monazite of, ~284~ separation of, ~156~ Cerous compounds, ~158~ Chalcolamprite, 12, 70 Chardonnet process, ~302~ Chlorides of rare earth group, ~121~ Chromates of rare earth group, ~129~ Churchite, 12, 80 Clamond mantles, ~268~ Cleveite, 13, 73 Cordylite, 13, ~80~ Cossyrite, 13 Cryptolite, ~84~ Cuprammonium process, ~303~ Crytolite, 13, 49 Davidite, 13, 59 Delorenzite, 13, ~56~ Derbylite, 13, ~59~ Drummond light, ~267~ Dysanalyte, 14, 71 Dysprosium, ~199~ history of, 195 separation of, 196 Edwardsite, 84 Elpidite, 14, 45 Endeiolite, 14, 70 Equivalent weight determination, ~153~ Erbium, atomic weight of, ~202~ detection of, ~203~ group, 199 history of, 194, ~201~ salts of, ~202~ separation of, 196 Erdmannite, 14, 45 Eremite, 84 Erikite, 14, 51 Ethylsulphates of rare earth group, ~127~ Eucolyte, 14, ~50~ Eucolyte-Titanite, 54 Eucrasite, 15, 49 Eudialite, 15, ~50~ Europium, atomic weight of, 188 compounds of, ~188~ history of, 185 Euxenite, 15, 66, ~68~ Eytlandite, 60 Fahnehjelm mantles, ~269~ Fergusonite, 15, 38, ~63~, 90 Ferrocyanides of rare earth group, ~123~ Ferro-titanium, ~326~ Florencite, 15, 51 Fluocerite, 15, 89 Fluorides of rare earth group, ~120~ Fluorspar, 2, 89, 102 Formates of rare earth group, ~133~ Freyalite, 16, 49 Gadolinite, 1, 16, ~33~, 91 Gadolinium, atomic weight of, 190 compounds of, ~190~ detection of, 191 history of, 184, ~189~ Geikielite, 16, 59 Gorceixite, 16, 88 Greenovite, 54 Gröthite, 26, 54 Guarinite, 16, 51 Gummite, 73 Hainite, 16, 70 Halogen oxy-salts of rare earth group, ~123~ Harmatite, 10, 81 Helium ratio, 104, ~106~ Hellandite, 16, ~42~ Hiortdahlite, 17, ~51~ Hjelmite, 17, 64 Holmium, compounds of, ~201~ history of, ~195~ separation of, 196 Homilite, 17, 51 Hussakite, 17, 87 Hydrides of rare earth groups, ~116~ Hydrotitanite, 17, 59 Hydroxides of rare earth groups, ~116~