noun ダウンロード 🔗共有 長石 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. " 多くのカウンターは、長石を含み、まだら模様の外観を与える御影石で作られています。 geology mineral material substance science AIとチャット語彙ゲーム読解練習