Feldspar

Alternative forms

• felspar

Origin

Feld, field (from Middle High German veld, from Old High German feld) + Spath, spar

Full definition of feldspar

Noun

1. (mineral) 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.

Related terms

• feldspathic
• feldspathoid

Derived terms

• feldsparlike