Diorite rock specimens from Cockermouth, Cumbria, is an intrusive igneous rock from the Ordovician period with a coarse, phaneratic texture composed of plagioclase feldspar, biotite mica as well as hornblende with intermediate chemistry. Found with the Skiddaw group, the rock samples are more suited for serious collectors and higher level education to describe the chemistry and mineralogy of various igneous groups. Available in 3 sizes and supplied in a card tray with an information label.