alkali feldspar उदाहरण वाक्य
उदाहरण वाक्य
- Pericline twinning is a type of crystal twinning which show fine parallel twin laminae typically found in the alkali feldspars microcline.
- The leucite tinguaites are usually pale grey or greenish in color and consist principally of nepheline, alkali feldspar and aegirine.
- The essential components of aplites are quartz and alkali feldspar ( the latter usually orthoclase or microperthite ), microcline and albite.
- With the addition of alkali feldspar replacing or becoming more dominant than calcic plagioclase theralites grade into foidal syenite, including shonkinite.
- By definition, granite is an igneous rock with at least 20 % quartz and up to 65 % alkali feldspar by volume.
- Minerals such as alkali feldspar, leucite, nepheline, sodalite, phlogopite mica, and apatite may be present in the groundmass.
- The intergrowth forms by exsolution due to cooling of a grain of alkali feldspar with a composition intermediate between K-feldspar and albite.
- If cooling is sufficiently slow, the alkali feldspar may exsolve to form separate grains with near-endmember albite and K-feldspar compositions.
- Take the alkali feldspar minerals for example, whose end members are albite, NaAlSi 3 O 8 and microcline, KAlSi 3 O 8.
- Within the lava dome rocks lie phenocrysts of amphibole, biotite, plagioclase, quartz, and titanite with some alkali feldspar in some domes.