A Summary of Progress in Petrography. in 1887-1896 |
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... pseudomorphs of asbestos after pyroxene are found in the vicinity , it is thought that the material analyzed may be of the same nature . Dawsonite and ittnerite occur at the Corporation Quarry , on the west side of Montreal Mountain ...
... pseudomorphs of asbestos after pyroxene are found in the vicinity , it is thought that the material analyzed may be of the same nature . Dawsonite and ittnerite occur at the Corporation Quarry , on the west side of Montreal Mountain ...
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... pseudomorphs of quartz described by Mallard . They have not the same density as melanophlogite , nor the same optical properties . The formation of the latter mineral is ascribed to the action of SO , on quartz . The author also ...
... pseudomorphs of quartz described by Mallard . They have not the same density as melanophlogite , nor the same optical properties . The formation of the latter mineral is ascribed to the action of SO , on quartz . The author also ...
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... pseudomorphs of opal and quartz after some unknown mineral.A little more than a year ago the nodular rose - red cudialite of Magnet Cove , Arkansas , was described by Hidden and Mackintosh.14 Recently crystals of the sub- stance have ...
... pseudomorphs of opal and quartz after some unknown mineral.A little more than a year ago the nodular rose - red cudialite of Magnet Cove , Arkansas , was described by Hidden and Mackintosh.14 Recently crystals of the sub- stance have ...
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... pseudomorphs of bryozoons , or of fragments of these.31 27 Neues Jahrb . f . Min . , etc. , 1891 , I. , p . 291 . 28 Retgers . Ib . , 1891 , I. , p . 276 . 29 Zeits . f . Kryst . , XVIII . , 1890 , p . 475 . 30 Ahrens . Ber . d ...
... pseudomorphs of bryozoons , or of fragments of these.31 27 Neues Jahrb . f . Min . , etc. , 1891 , I. , p . 291 . 28 Retgers . Ib . , 1891 , I. , p . 276 . 29 Zeits . f . Kryst . , XVIII . , 1890 , p . 475 . 30 Ahrens . Ber . d ...
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... pseudomorphs of phillipsite after olivine in the leucitites ; augite crystals with second- ary twinning lamellæ produced by pressure in the nephelinites and feldspathic basalts ; zonal augites in the leucitites , with an extinction ...
... pseudomorphs of phillipsite after olivine in the leucitites ; augite crystals with second- ary twinning lamellæ produced by pressure in the nephelinites and feldspathic basalts ; zonal augites in the leucitites , with an extinction ...
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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...