Beyerite

Rare beyerite on matrix from the classic Mesopotamia 504 Farm, Mesopotamia Copper Valley, Khorixas, Kunene Region, Namibia. The specimen shows yellow to yellow-green beyerite forming fine crystalline to microcrystalline aggregates coating the matrix, displaying the typical earthy to slightly silky appearance known for this species.

Beyerite is a rare carbonate mineral, first described in 1868 and named after Heinrich Beyer, a German mineralogist. It forms as a secondary mineral in the oxidation zone of bismuth- and copper-bearing deposits. The Mesopotamia Copper Valley is a well-documented locality for secondary bismuth carbonates and has produced some of the finest known African beyerite specimens.

At this locality, beyerite is commonly associated with secondary copper minerals, most notably malachite, which is consistent with documented Mesopotamia material. Beyerite is considered rare, and well-developed yellow aggregates such as this represent a characteristic example for the species.

The specimen originates from the former collection of C. Strömpl, an amateur mineralogist.