FTP, identify this group of minerals that ranks number 6 on the Mohs' scale and is the most abundant group in the Earth's crust.
About 4000 tons of this type of mineral are used annually in the ceramics industry, and the gem variety moonstone is used in jewelry. Its pure variety is colorless and transparent, but impurities like barium can make it opaque. Orthoclase, albite, anorthite, and celsian are the plagioclase types, which have a low potassium content, while alkali varieties like microcline and orthoclase have little sodium or calcium. FTP, identify this group of minerals that ranks number 6 on the Mohs' scale and is the most abundant group in the Earth's crust.
About 4000 tons of this type of mineral are used annually in the ceramics industry, and the gem variety moonstone is used in jewelry.
feldspar or felspar