Home > Copper Minerals II – September 8 > MS1118 Tyrrellite in Umangite

Tyrrellite in Umangite - Sold

Tyrellite is a copper cobalt selenide, specifically a member of the linneaite group (Yang et al. 2007). The name tyrrellite honors Joseph Burr Tyrell (1858-1957), the first geologist to study the discovery area (Harris, 1970). The bulk of this specimen is massive umangite, a copper selenide. Umangite takes its name from the Sierra de Umango, Argentina, place of its first discovery (Klockmann, 1891). Tyrrellite forms brassy grains to perhaps 0.5 mm in a tarnished purple-black umangite. The whole specimen seems to represent a narrow vein section, surficially altered to various green copper minerals.

This specimen was part of the personal collection of Ralph Merrill, proprietor of the prolific mail order business Minerals Unlimited. The specimen also carries a Geological Survey of Canada label. Merrill's collection card and label also ship with the specimen.