29 results about "Feldspar" patented technology

Feldspars (KAlSi₃O₈ – NaAlSi₃O₈ – CaAl₂Si₂O₈) are a group of rock-forming tectosilicate minerals that make up about 41% of the Earth's continental crust by weight. Feldspars crystallize from magma as veins in both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks.