As the name suggests, Cornwallite was first found in the south-westernmost county in England - Cornwall. Compared with the chemically related copper arsenates: Liroconite, Clinoclase and Olivenite, it often gets overlooked, and, while those were originally described during the late 18th and early 19th centuries it was not until 1846 that Cornwallite was recognized as a new species. Part of the reason was no doubt the fact that it never forms obvious discrete individual crystals, rather as mid-green smooth botryoidal crystals coating veinstone and lining cavities associated with other copper arsenates. This miniature specimen, which is from the Type Locality at Wheal Gorland, is richly invested with Cornwallite as microbotryoidal coatings on white Quartz veinstone and presents its classic association with glossy small seed-like Olivenite crystals. Ex Malcolm Southwood Collection, no. MS 2000.078.
