A Summary of Progress in Petrography. in 1887-1896 |
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Page 5
... silica by algæ and mosses . Waters too poor in silica to form deposits of this substance by cooling or evaporation , are often dammed back by thick jelly - like accumulations of silica , separated from the water by plant life , which is ...
... silica by algæ and mosses . Waters too poor in silica to form deposits of this substance by cooling or evaporation , are often dammed back by thick jelly - like accumulations of silica , separated from the water by plant life , which is ...
Page 11
... silica , tantalum , boron , and fluorine .-- Cohenite is described . by Weinschenck 17 from the meteoric iron of Magura , Hungary . When dissolved in hydrochloric acid the meteor leaves a residue in which lit- tle prismatic tin white ...
... silica , tantalum , boron , and fluorine .-- Cohenite is described . by Weinschenck 17 from the meteoric iron of Magura , Hungary . When dissolved in hydrochloric acid the meteor leaves a residue in which lit- tle prismatic tin white ...
Page 6
... silica rather than with the increase of iron.- -Atelesite , analyzed by Busz , yielded : As2O 14.12 Bi , O , 82.41 Fe2O H2O .51 1.92 5 Quart . Jour . Geol . Soc . , 1889 , p . 626 . 6 American Geologist , Nov. 1889 , p . 291 . 7 ...
... silica rather than with the increase of iron.- -Atelesite , analyzed by Busz , yielded : As2O 14.12 Bi , O , 82.41 Fe2O H2O .51 1.92 5 Quart . Jour . Geol . Soc . , 1889 , p . 626 . 6 American Geologist , Nov. 1889 , p . 291 . 7 ...
Page
... silica to 300 ° under the same conditions . Microcline gave tridymite plates . A mixture of metallic iron , iron oxide and amorphous silica produced litte black amorphous plates of ilmenite and crystals of magnetite . The syntheses are ...
... silica to 300 ° under the same conditions . Microcline gave tridymite plates . A mixture of metallic iron , iron oxide and amorphous silica produced litte black amorphous plates of ilmenite and crystals of magnetite . The syntheses are ...
Page 6
... silica differing from quartz and chal- cedony , since it possesses optical properties that differ from those of these minerals . Its index of refraction for sodium light is 1.446.- Heliophyllite , from Pajsberg is a shining , sulphur ...
... silica differing from quartz and chal- cedony , since it possesses optical properties that differ from those of these minerals . Its index of refraction for sodium light is 1.446.- Heliophyllite , from Pajsberg is a shining , sulphur ...
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Common terms and phrases
acute bisectrix Al,O Amer AMERICAN NATURALIST amphibole analysis andesites apatite augite axial ratio basalt biotite bisectrix brown Bull calcite Colby University color colorless composition containing cordierite corresponding described diabase diorites double refraction dykes Edited by Dr epidote eruptive Fe,O feldspar FeO CaO MgO FeO MnO Förh formula gabbro garnet Geol gneiss grains granite green ground-mass H₂O hardness hexagonal hornblende inclusions isomorphous Jour Kryst Lacroix lamellæ lithophysæ lustre magma magnetite MAKERS SYRACUSE manganese mica microlites mineral occurs MINERALOGY AND PETROGRAPHY.¹ molecule monoclinic Na,O Na₂O nepheline Neues Jahrb olivine optical angle optical axes original orthoclase orthorhombic Petrog PETROGRAPHY.¹ Petrographical phenocrysts plagioclase pleochroic porphyritic porphyritic crystals pressure prismatic produced pyroxene quartz regarded resembles rhombohedral rocks scapolite schists silica small crystals specific gravity spherulites structure substance symmetry thin section tion twinning plane variety W. S. Bayley Waterville yellow yielded Zeits
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Page 5 - The olivine is surrounded by a reactionary rim consisting of an inner zone of hypersthene and an outer one of actinolite.