Metamorphic—changed; usually by heat or pressure to a different form but
the same composition
Mica—a silicate mineral that forms sheets or layers and contains
aluminum, hydroxyl, and alkali ions: K₂Al₄Si₆Al₂O₂₀(OH,F)₄,
K₂(Mg,Fe)₆Si₆Al₂O₂₀(OH,F)₄
Mineral—a naturally occurring inorganic substance with an ordered
structure; rocks are made of one or more minerals