FELDSPAR TYPES

* FELDSPAR TYPES :-

Feldspars occur as solid solutions between their principal end member (Na, K, or Ca) compositions. Commercial products in most cases are employed for their chemistry (aluminum and alkali content) and are generally characterized accordingly. Certain products are more broadly described in geological terms.

·        Alkaline feldspar − This is feldspar with chemistry ranging between the potassium and sodium end members.

·     Plagioclase feldspar − This is feldspar with chemistry ranging between the sodium and calcium end members.

·        Potash spar − Potash spar is principally orthoclase or microcline and contains at least 10% K2O.

·        Soda spar − Soda spar is mostly albite and contains at least 7% Na2O.

·        Calcium spar − This is principally anorthite.

·        Aplite − Aplite is a grainy granitic (containing quartz and alkali feldspar) rock containing a substantial proportion of plagioclase. It is also called lime-soda feldspar. Low-iron aplite is sold in the US for glassmaking.

·        Feldspathic sand − This is natural silica sand containing 10-35% feldspar, usually potash spar or soda spar. This sand is described, in decreasing feldspar content, as river sand, dune sand, and beach sand.