A Summary of Progress in Petrography. in 1887-1896 |
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Page 2
... planes in several minerals . He describes rutile from the Urals in which the usual cleavage parallel to ∞ Poo , is wanting , its place being taken by a parting parallel to P∞ , but whether as a result of twinning or not , Mügge is ...
... planes in several minerals . He describes rutile from the Urals in which the usual cleavage parallel to ∞ Poo , is wanting , its place being taken by a parting parallel to P∞ , but whether as a result of twinning or not , Mügge is ...
Page 4
... twinning in sphene , and finds the twinning plane to be in the zone between P and P ( DesCloizeaux's position ) , and not to coincide exactly with -2P , as determined by Williams . He ascribes the striations frequently observed in the ...
... twinning in sphene , and finds the twinning plane to be in the zone between P and P ( DesCloizeaux's position ) , and not to coincide exactly with -2P , as determined by Williams . He ascribes the striations frequently observed in the ...
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... twinned , but more frequently twinned forms are found in which the twinning planes are ∞ P ( corresponding to DesCloizeaux twins par . ∞ P∞ ) , ∞ P ( occasionally ) , P ( ? ) , and oP ; and a fifth form in which the twinning plane ...
... twinned , but more frequently twinned forms are found in which the twinning planes are ∞ P ( corresponding to DesCloizeaux twins par . ∞ P∞ ) , ∞ P ( occasionally ) , P ( ? ) , and oP ; and a fifth form in which the twinning plane ...
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... plane is the base , with b the positive acute bisectrix . A new analysis of carefully purified material shows slight ... twinning plane is the ortho- pinacoid . When placed in the conventional position for pyroxene its axial ratio ...
... plane is the base , with b the positive acute bisectrix . A new analysis of carefully purified material shows slight ... twinning plane is the ortho- pinacoid . When placed in the conventional position for pyroxene its axial ratio ...
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... twinning par- allel to the orthopinacoid . These monoclinic natrolites ... Plane of the optical axes is ∞ P , and is the acute bisectrix . 2 Vna 87 ... plane of its optical axis the clinopinacoid , with the positive acute ...
... twinning par- allel to the orthopinacoid . These monoclinic natrolites ... Plane of the optical axes is ∞ P , and is the acute bisectrix . 2 Vna 87 ... plane of its optical axis the clinopinacoid , with the positive acute ...
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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.