perthite उदाहरण वाक्य

This is coloured yellow brown to pink and contains fine crystals of perthite, and oligoclase and quartz, coloured by limonite.
The feldspar has partly unmixed on the micro-scale to form a perthite, and the presence of the alternating alkali feldspar and titanomagnetite present.
Sodalite-syenites in which sodalite very largely or completely takes the place of nepheline occur in Greenland, where they contain also microcline-perthite, aegirine, arfvedsonite and eudialyte.
The bedrock of the landscape around Gold Butte Peak and nearby Bonelli Peak consist of gray, Proterozoic, porphyritic perthite-quartz-biotite granites and quartz monzonites that are also classified as rapakivi granite.
Because Na and K are extremely mobile by solid-state diffusion, cooling gives rise to multiple forms of unmixing products, e . g . various kinds of perthite . " Due to slow reaction kinetics, feldspars usually do not attain equilibrium states and thus their thermodynamic behaviour is not yet fully understood ."

"' Perthite "'is used to describe an intergrowth of two feldspars : a host grain of potassium-rich alkali feldspar ( near K-feldspar, KAlSi 3 O 8, in composition ) includes exsolved lamellae or irregular intergrowths of sodic alkali feldspar ( near albite, NaAlSi 3 O 8, in composition ).
Callander Bay contains uncommon rocks such as nepheline syenite and carbonatite and the minerals : aegirine, amphibole, analcime, apatite, barite, biotite, calcite, cancrinite, chalcopyrite, chlorite, diopside, dolomite, fluorite, garnet, hematite, kaersutite, magnetite, muscovite, nepheline, olivine, perthite, pyrite, pyroxene and pyrrhotite.