Cornubite (RARE - Type Locality) ex British Musuem

Item Description

Cornubite is a rare anhydrous Cu-arsenate, the triclinic dimoprh of monoclinic Cornwallite. It was named in 1958 for Cornubia, the medieval Latin name for Cornwall (MINDAT). This small extinct Cornwall Cu-Sn-Ag mine has an intermittent production history from about 1792 to 1855 and is the Type Locality. Mineral specimens are very uncommon from here and verified Cornubite specimens are EXTREMELY RARE. A 6 mm area on one face hosts a green globular waxy lustre Cornubite mass and what appears to be a few rare tabular crystals in a spray. Pods of a green amorphous Cu-arsenate are richly scattered on all sides of the miniature matrix, which includes mica and quartz. Collected by Arthur Kingsbury in 1958. Arthur was a prominent English field collector, collector, author and research assistant in mineralogy at Oxford University. His extensive collection was donated to the British Museum after his death in 1968. Ex Bristish Museum of Natural History. It was verified as Cornubite with XRD by Mike Rumsey of the BMNH in 2007. A VERY RARE specimen from the Type Locality and obtained via exchange. A MUST for the locality or species collector.