A Summary of Progress in Petrography. in 1887-1896 |
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Page 1885
... hornblende , augite , and cordierite . The last - named mineral occurs in the form of irregular grains associated with quartz , and also in well - developed crystals , with a pleochroism : A = yellowish - white ; B = dark violet ; C ...
... hornblende , augite , and cordierite . The last - named mineral occurs in the form of irregular grains associated with quartz , and also in well - developed crystals , with a pleochroism : A = yellowish - white ; B = dark violet ; C ...
Page 1893
... hornblende , augite , and cordierite . The last - named mineral occurs in the form of irregular grains associated with quartz , and also in well - developed crystals , with a pleochroism : A = yellowish - white ; B = dark violet ; C ...
... hornblende , augite , and cordierite . The last - named mineral occurs in the form of irregular grains associated with quartz , and also in well - developed crystals , with a pleochroism : A = yellowish - white ; B = dark violet ; C ...
Page 1901
... hornblende schists and other foliated rocks . The effect of pressure is shown in the broken condition of many of the crystals in the rocks ; crushed and sundered plagioclase , apatite , hornblende , leucoxene , tourmaline and quartz are ...
... hornblende schists and other foliated rocks . The effect of pressure is shown in the broken condition of many of the crystals in the rocks ; crushed and sundered plagioclase , apatite , hornblende , leucoxene , tourmaline and quartz are ...
Page 1902
... hornblende - syenite gneiss occurs , and in it several pieces of twinned sphene were observed . The two craters Mte . Cimi- no and the Lago di Vico3 in central Italy , though but parts of the same great volcano , like Mts . Somma and ...
... hornblende - syenite gneiss occurs , and in it several pieces of twinned sphene were observed . The two craters Mte . Cimi- no and the Lago di Vico3 in central Italy , though but parts of the same great volcano , like Mts . Somma and ...
Page 2
... hornblende constituent has a well- developed parting parallel to P. Parting parallel to an octahedral face , in many members of the spinel group , is declared to be the result of polysynthetic twinning . Calcite , with a parting ...
... hornblende constituent has a well- developed parting parallel to P. Parting parallel to an octahedral face , in many members of the spinel group , is declared to be the result of polysynthetic twinning . Calcite , with a parting ...
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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
Popular passages
Page 5 - The olivine is surrounded by a reactionary rim consisting of an inner zone of hypersthene and an outer one of actinolite.