How to sign: 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
Similiar / Same: mica
Categories: mineral, translucent substance, transparent substance
Within this category: biotite, lepidolite, muscovite, paragonite, phlogopite, zinnwaldite