Home > Copper Minerals – January 21 > MS1492 Cornwallite after Clinoclase

Cornwallite after Clinoclase - Sold

Cornwallite is a hydrous copper arsenate. Zippe (1847) named the mineral species after Cornwall, England, source of the original mineral. Clinoclase is another hydrous copper arsenate. The mineral name combines Greek roots clinon incline and klan break, alluding to its monoclinic cleavage.This is an unusual pseudomorph involving two copper arsenate species. Originally cornflower blue clinoclase has changed to bright green cornwallite. The bladed crystals are approximately 1 mm long, forming a coverage 2.5 cm across on a breccia fragment. Much rarer than unaltered clinoclase from this locality.