A grouping of diamond shaped muscovite crystals. Muscovite is also a type of mica. Micas part in a 'book-like' fashion, where each book contains many, many sheets, and can easily be peeled back and pulled apart. The crystals are also very flexible. Muscovite has been used as glass for woodburning stoves due to its tolerance for heat, which is much higher than standard glass. Sample measures 2 inches long.