A Summary of Progress in Petrography. in 1887-1896 |
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Page 11
... formula ( Ca , Mn ) , Na H ( SiO , ) , — a pectolite with a tenth of its calcium replaced by manganese . In its optical properties the new mineral agrees well with the view that it is closely allied to pectolite . Its axial plane is Poo ...
... formula ( Ca , Mn ) , Na H ( SiO , ) , — a pectolite with a tenth of its calcium replaced by manganese . In its optical properties the new mineral agrees well with the view that it is closely allied to pectolite . Its axial plane is Poo ...
Page 14
... formulas of the garnet type . Die Japanischen Inseln . , 1st Lief . , Berlin , Parey , 1890 . Neues Jahrb . f . Min . , etc. , B. B. VII . , p . 133 . • Zeits . f . Kryst . , XVIII . , 1890 , p . 209 . WTI Fe as with seri the they ana ...
... formulas of the garnet type . Die Japanischen Inseln . , 1st Lief . , Berlin , Parey , 1890 . Neues Jahrb . f . Min . , etc. , B. B. VII . , p . 133 . • Zeits . f . Kryst . , XVIII . , 1890 , p . 209 . WTI Fe as with seri the they ana ...
Page 14
... formula Na [ Al ( S , Na ) ] Al , ( SiO ) ,. The authors then discuss the nature of artificial ultramarine , and conclude that it is a mixture of five isomorphous substances . A microscopical examination of lapis - lazuli reveals the ...
... formula Na [ Al ( S , Na ) ] Al , ( SiO ) ,. The authors then discuss the nature of artificial ultramarine , and conclude that it is a mixture of five isomorphous substances . A microscopical examination of lapis - lazuli reveals the ...
Page 15
... formula ascribed to the substance differs from Frenzel's formula in lacking one molecule of water . Ferronatrite , although obtainable only in white or grayish cleavage masses , is thought to be hexagonal . Its indices of refraction are ...
... formula ascribed to the substance differs from Frenzel's formula in lacking one molecule of water . Ferronatrite , although obtainable only in white or grayish cleavage masses , is thought to be hexagonal . Its indices of refraction are ...
Page 17
... formula ( FeMn ) , ( PO , ) , + 3H , O . Fairfieldite is in transparent foliated masses of a whitish or greenish - white color and a brilliant lustre , inclining to pearly on the perfect cleavage . Its composition agrees with the symbol ...
... formula ( FeMn ) , ( PO , ) , + 3H , O . Fairfieldite is in transparent foliated masses of a whitish or greenish - white color and a brilliant lustre , inclining to pearly on the perfect cleavage . Its composition agrees with the symbol ...
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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...