A Summary of Progress in Petrography. in 1887-1896 |
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Page 11
... double refraction is positive , and the dispersion is strong s > p . - Pinakiolite and trimerite are both new miner- als from the Manganese Mines in Sweden . The name of the first refers to its occurrence in small , tabular crystals ...
... double refraction is positive , and the dispersion is strong s > p . - Pinakiolite and trimerite are both new miner- als from the Manganese Mines in Sweden . The name of the first refers to its occurrence in small , tabular crystals ...
Page 14
... refractive phenomena , such as the refractive index for different wave lengths . The third and fourth contain ... double refraction , are explained as due to the manner of growth . Many new ideas are gathered from the study , one ...
... refractive phenomena , such as the refractive index for different wave lengths . The third and fourth contain ... double refraction , are explained as due to the manner of growth . Many new ideas are gathered from the study , one ...
Page 20
... refracting mineral occurs in the nepheline - syenite of a " massif ” in the Kole Peninsula , Russia . Since its ... double refraction . Leverrierite is found as a metamorphic constituent in carbonaceous clay slates , and in ...
... refracting mineral occurs in the nepheline - syenite of a " massif ” in the Kole Peninsula , Russia . Since its ... double refraction . Leverrierite is found as a metamorphic constituent in carbonaceous clay slates , and in ...
Page
... double refraction calculated for a vacuum , and a fourth represents the variations in the angle of the prism used produced by different temperatures . Without entering into the details of the investigation , it may be said that the ...
... double refraction calculated for a vacuum , and a fourth represents the variations in the angle of the prism used produced by different temperatures . Without entering into the details of the investigation , it may be said that the ...
Page
... double refraction is positive . It is one of the youngest of the constituents of the eleolite - syenite in which it occurs . The negatively refracting eucolite , of about the same compo- sition as eudialite , appears in brownish ...
... double refraction is positive . It is one of the youngest of the constituents of the eleolite - syenite in which it occurs . The negatively refracting eucolite , of about the same compo- sition as eudialite , appears in brownish ...
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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...