any of various minerals consisting of hydrous silicates of aluminum or potassium etc. that crystallize in forms that allow perfect cleavage into very thin leaves; used as dielectrics because of their resistance to electricity.

• 由含水硅酸铝或硅酸钾等组成的矿物，呈晶体状，能分裂成极薄的片状，具有良好的电绝缘性。