Tsumcorite is a rare lead/zinc/iron arsenate that occurs only at Tsumeb in such good crystallized specimens. It is seldom found and specimens are usually both small and unimpressive. Barlow's, for example, was only a miniature of similar syle to this piece ... 1/5 the size! This is a monstrous piece for the species, with excellent color and complete coverage, and so quite significant! It is certainly the richest single piece I know of that has been for sale in recent years. 8 x 5 x 4 cm