Mica is the general term for the group of sheet silicate minerals possessing perfect cleavage, and composition of individual micas varies. From Wikipedia:"Chemically, micas can be given the general...
Muscovite is but one of a number of micaceous minerals.
Mica is flexible; Mica has a flat transparency, sight glass.
Biotite mica contains iron and/or magnesium, but muscovite mica does not.
A mica is a mineral for a igneous rock