Phyllite is a foliated metaorphic rock formed from slate which has been further metamorphosed. These specimens from Cumbria show good, fine cleavage and a silky metallic lustre. Supplied in lots of 1 kg.
Phyllite is a type of foliated metamorphic rock created from a slate or pelite protolith that has further metamorphosed so that very fine grained white mica achieves a preferred orientation. It is primarily composed of quartz, sericite mica, and chlorite. Sometimes minute crystals of graphite, sericite, or chlorite, or the translucent fine-grained white mica, impart a silky, sometimes golden sheen to the surfaces of cleavage, called "phyllitic luster". These examples are from Cumbria, Uk and come in bags weighing 1 kilogram and have a data label inside.