A Summary of Progress in Petrography. in 1887-1896 |
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Page 1888
... specific gravity is 4.575 , and its hardness 5-5.5 . It is soluble in hydrochloric acid , decrepitates when heated , and breaks into an infusible and insoluble powder . Its com- position is : 2 3 SiO , PbO Tho , MnO FeO CaO Al , O , Ce ...
... specific gravity is 4.575 , and its hardness 5-5.5 . It is soluble in hydrochloric acid , decrepitates when heated , and breaks into an infusible and insoluble powder . Its com- position is : 2 3 SiO , PbO Tho , MnO FeO CaO Al , O , Ce ...
Page 1889
... specific gravity of 3.24-3.31 . It occurs in two varieties , the compositions of which are as follows : SiO , Al , O , FeO CaO Loss . Colorless : 36.6 32.5 1.9 23.9 2.7 Yellow : 38.3 31.9 4.4 23.5 2.7 -Pleonektite occurs with ...
... specific gravity of 3.24-3.31 . It occurs in two varieties , the compositions of which are as follows : SiO , Al , O , FeO CaO Loss . Colorless : 36.6 32.5 1.9 23.9 2.7 Yellow : 38.3 31.9 4.4 23.5 2.7 -Pleonektite occurs with ...
Page 1896
... specific gravity is 4.575 , and its hardness 5-5.5 . It is soluble in hydrochloric acid , decrepitates when heated , and breaks into an infusible and insoluble powder . Its com- position is : 2 Sio , PbO Tho , MnO FeO CaO AIO , Ce2O ...
... specific gravity is 4.575 , and its hardness 5-5.5 . It is soluble in hydrochloric acid , decrepitates when heated , and breaks into an infusible and insoluble powder . Its com- position is : 2 Sio , PbO Tho , MnO FeO CaO AIO , Ce2O ...
Page 1897
... Sp . Gr = 3.87 . Its composition is : As2O Sb , Mn , O , Fe2O , MnO CaO MgO HO 20.2 1.5 35.8 .4 29. I 1.7 9.9 The ... specific gravity of 3.24-3.31 . It occurs in two varieties , the compositions of which are as follows : Sio , ALO ...
... Sp . Gr = 3.87 . Its composition is : As2O Sb , Mn , O , Fe2O , MnO CaO MgO HO 20.2 1.5 35.8 .4 29. I 1.7 9.9 The ... specific gravity of 3.24-3.31 . It occurs in two varieties , the compositions of which are as follows : Sio , ALO ...
Page 1898
... Specific gravity = 4.39 . — Messelite is found in aggregates of colorless or brown tabular crystals in a clay slate at Messel , a station on the railroad between Darmstadt and Aschaffenberg , Hessen . The crystals 19 are monoclinic ...
... Specific gravity = 4.39 . — Messelite is found in aggregates of colorless or brown tabular crystals in a clay slate at Messel , a station on the railroad between Darmstadt and Aschaffenberg , Hessen . The crystals 19 are monoclinic ...
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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.