Olivenite crystals from the Tsumeb Mine, Otavi Mountains, Namibia, Ilse Baer collection – micromount as unique piece
This micromount specimen with Olivenite crystals from the Tsumeb Mine, Otavi Mountains, Namibia, from the Ilse Baer collection displays numerous dark lustrous crystals on a greenish finely textured matrix. The crystals are scattered across the surface and form small well recognizable groups with a bright vitreous luster. The strong contrast between the dark crystals and the lighter matrix gives the specimen a very distinctive appearance.
The combination of attractive crystals and the famous origin from the world renowned Tsumeb Mine makes this micromount an appealing collector specimen, especially for enthusiasts of rare secondary arsenate minerals from classic localities.
This micromount specimen dates from before 1972.
Geology & Origin
Olivenite is a copper arsenate hydroxide and is a typical secondary mineral of the oxidation zone of polymetallic deposits. It forms through the weathering of arsenic bearing copper ores under oxidizing conditions. The Tsumeb Mine in Namibia is one of the most important classic mineral localities in the world and is famous for its extraordinary diversity of rare secondary copper and lead minerals formed by complex geochemical processes in the oxidation zone.