A Summary of Progress in Petrography. in 1887-1896 |
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Page 8
... calcite , dolomite , and small grains of the original mineral . The amphibole in the rocks is pargasite . Two varieties of spinel were ob- served , one a violet and often transparent variety , and the other green pleonast . The violet ...
... calcite , dolomite , and small grains of the original mineral . The amphibole in the rocks is pargasite . Two varieties of spinel were ob- served , one a violet and often transparent variety , and the other green pleonast . The violet ...
Page 9
... calcite , occasionally quartz , and frequently vesuvianite , of which latter it is possible to isolate beautiful amber - yellow crystals of the variety egeran . In the second article by the same author is a discussion of the changes ...
... calcite , occasionally quartz , and frequently vesuvianite , of which latter it is possible to isolate beautiful amber - yellow crystals of the variety egeran . In the second article by the same author is a discussion of the changes ...
Page 10
... Sci . , Sept. , 1890 , p . 246 . Neues Jahrb . f . Min . , etc. , 1890 , II . , p . 267 . 7 J. F. Williams . Zeits . f . Kryst . , XVII . , 1890 , p . 386 . ∞ Correcting for the small amount of calcite present , MAKERS.
... Sci . , Sept. , 1890 , p . 246 . Neues Jahrb . f . Min . , etc. , 1890 , II . , p . 267 . 7 J. F. Williams . Zeits . f . Kryst . , XVII . , 1890 , p . 386 . ∞ Correcting for the small amount of calcite present , MAKERS.
Page 11
William Shirley Bayley. ∞ Correcting for the small amount of calcite present , the analysis cor- responds with the formula ( Ca , Mn ) , Na H ( SiO , ) , — a pectolite with a tenth of its calcium replaced by manganese . In its optical ...
William Shirley Bayley. ∞ Correcting for the small amount of calcite present , the analysis cor- responds with the formula ( Ca , Mn ) , Na H ( SiO , ) , — a pectolite with a tenth of its calcium replaced by manganese . In its optical ...
Page 14
... calcite , pyrite , and a muscovite - like mineral , together with a little scapolite , plagioclase , orthoclase , apatite , sphene , zircon , and an unknown , probably positive , uniaxial mineral . — The interesting Chilian minerals ...
... calcite , pyrite , and a muscovite - like mineral , together with a little scapolite , plagioclase , orthoclase , apatite , sphene , zircon , and an unknown , probably positive , uniaxial mineral . — The interesting Chilian minerals ...
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Common terms and phrases
acid Al,O alteration Amer AMERICAN NATURALIST analysis andalusite angle aragonite augite axial ratio basalts beryl biotite brucite Bull calcite calcium chlorite cleavage Colby University color colorless composition constituents containing cordierite corresponding crystalline crystals density described diabase double refraction dyke eruptive rocks Fe,O Fe₂O feldspar FeO MgO CaO FeO MnO forms formula Franc gabbro-diorites gabbros garnet Genth gneisses granite granulites ground-mass H₂O habit hexagonal hornblende humite hypersthene imbedded inclusions Jour Kryst leucite masses melanophlogite metacinnabarite mica mineral MINERALOGY AND PETROGRAPHY.¹ Mitth molecules muscovite Neues Jahrb nosean occur olivine optical original orthoclase ottrelite parallel Penfield Petrog PETROGRAPHY.¹ Petrographical phenacite plagioclase plane plates polymorphism prismatic produced pseudomorphs pyroxene quartz regarded rock individual Rosenbusch schistose schists serpentine silica sodium soluble specific gravity specimens spinel structure substance sulphur symmetry tabular temperature tonalite tourmaline twinned varieties W. S. Bayley Waterville yielded Zeits zircon zone
Popular passages
Page 19 - The plane of the optical axes is perpendicular to the plane of symmetry, and makes with c an angle of °7 in acute /9. A = b. 2H na = 104° 27'.
Page 14 - The larger part of the dust is thought to be a sediment from the air, and to have been obtained by it from a region of crystalline schists. The chondri, on the other hand, are thought to be of cosmic origin, since they are similar to the chondri obtained in deep-sea soundings. If the amount of the dust collected from the snow in Greenland represents the fall of one year, the total amount falling upon the entire surface of the earth in this time is 125 million kilograms, equivalent to a cube of thirty-one...
Page 14 - Wiilfing 21 for investigation, by whom it has been found to consist in greater part of feldspar, quartz, mica, and hornblende. There are present in it also garnet, zircon, magnetite, augite, and sillimanite, and with them is mixed a nitrogenous organic substance. The most interesting constituents of the dust...