muscovite mica from a pegmatite near Coronel Murta, Minas Gerais, Brazil - display specimen Select a set: You can

Select a set: You can select a set by telling us what is in the photo with it

000 feet below the San Joaquin Valley floor

were mobilized either by magmatic or metamorphic processes in the underlying crystalline rocks or by the compaction of Triassic platform carbonates

Often they are completely mineral-filled

muscovite mica from a pegmatite near Coronel Murta, Minas Gerais, Brazil - display specimen Select a set: You canmuscovite mica KAL3Si3O10(OH)2 Coronel Murta, Minas Gerais, Brazil Muscovite is a common rock forming mineral. In pegmatites, which are essentially giant crystal granitic rocks, muscovite forms large books and can be cleaved into large sheets. It is mined commercially for use as an insulator in transformers and electrical equipment. Scrap muscovite, small flakes, is used as a filler or extender in paints. Transparent in thin sheets, muscovite is