8 letters · 14 points in Scrabble
noun any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium
originPartial calque of German Feldspat, formed from Feld (“field”) + Spat (“spar”), the second element replaced with the English cognate spar.
Etymology from Wiktionary, CC BY-SA 3.0