noun🔗ShareFeldspathsAny 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."Many granite countertops are made up of quartz, mica, and feldspars. "De nombreux plans de travail en granit sont composés de quartz, de mica et de feldspaths.geologymineralmaterialscienceChat with AIVocabulary GamePractice Reading