Home > Pseudomorphs – March 3 > MS1525 Goethite after Tennantite

Goethite after Tennantite - Sold


Tennantite is a copper arsenic sulfide. At Tsumeb, the mineral typically contains minor iron and minor antimony. The mineral name honors professor Smithson Tennant (1761-1815), chemist at Oxford University. Two brothers wrote seperate papers on the species, (Philips, 1819; Philips, 1819), the second of which proposed the species name.

In this specimen tennantite has completely oxidized and undergone nearly complete leaching of its copper. A prominent tetrahedral crystal, 4 cm on edge, has changed to a mixture of goethite, duftite, and dolomite. This pseudomorph has significant void space, much of its original constituents has dissolved away. The matrix is quartz-rich, and minor cerussite is present. At the base of the main crystal, cavities into the pseudomorph reveal its internal complexity. Likely from the First Oxidation Zone. Carries a David New label. Nice piece form a defunct locality.