Biotite muscovite granite specimens from St. Austell in Cornwall, UK of Permian age is a coarse grained igneous rock composed of quartz, plagioclase feldspar, biotite and muscovite. The rock is part of the St. Austell pluton which formed 280 million years ago. An off white colour with gold and black flecks of micas, the rock has a unique chemistry and resulted in the rich mineralisation of ores in the area. The samples are suitable for collectors and educational use to show granite variants, available in three sizes. Each piece will come supplied in a card tray with an information label.