

orthoclase
Meanings
Related Words
feldspar noun
/ˈfɛldˌspɑr/ /ˈfɛldˌspɑːr/
Any of a large group of rock-forming minerals that, together, make up about 60% of the earth's outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal constituents of igneous and plutonic rocks.