noun 다운로드 🔗공유 장석 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. Examples : "Many countertops are made with granite, which contains feldspar, giving them their speckled appearance. " 많은 조리대는 장석을 포함하는 화강암으로 만들어져 얼룩덜룩한 외관을 띕니다. geology mineral material substance science AI와 채팅어휘 게임독해 연습