DetailsDiorite is a grey to dark-grey intermediate intrusive igneous rock composed principally of plagioclase feldspar (typically andesine), biotite, hornblende, and/or pyroxene. It may contain small amounts of quartz, microcline, and olivine. Zircon, apatite, sphene, magnetite, ilmenite, and sulfides occur as accessory minerals. These particular samples were collected in Cumbria, UK. Each specimen is supplied in a labelled card tray.