Vesignieite

specimen number:
2133279

location:
Mashamba West Mine, Lualaba, DR Congo

description:
Deep green micro crystals on matrix. Nice example for the species and locality.

The Mashamba West mine, situated near the major copper-producing city of Kolwezi within the Lualaba Province of the Democratic Republic of the Congo, is a prolific industrial open-cast excavation celebrated among mineralogists for yielding extraordinary primary ores alongside rare secondary species like vesignieite, a scarce copper barium vanadate. Geologically, this major deposit is located in the western sector of the famous Central African Copperbelt, where stratiform copper and cobalt mineralization is strictly hosted within the highly deformed, Precambrian-age dolomites, dolomitic sandstones, and shales of the Roan Group's Serie des Mines. Intense regional supergene weathering and groundwater circulation through complex fault networks oxidized the primary sulfide bodies, deeply altering the dolomitic host rock and precipitating an exotic array of secondary minerals, including dark olive-green pseudohexagonal crystal aggregates of vesignieite inside porous solution cavities and pocket horizons. Historically, large-scale stripping and extraction at the Mashamba West pit began under the state-owned operator Gecamines during the late twentieth century as part of the massive Dikuluwe-Mashamba open-pit complex, producing vast amounts of copper and cobalt before entering periods of reduced output and partial inactivity near the turn of the century. Following modern corporate reorganizations, the mine experienced significant structural redevelopment and a major capacity expansion completed in June 2021 under the privately joint-operated Sicomines copper-cobalt project. Through 2026, active large-scale mechanized quarrying continues to expand the deep pit, ensuring that Mashamba West remains a vital pillar of global industrial metal production while historically preserving its status as a premier African reference locality.

Questions about this specimen?
Send an email or call us: 314-341-1811.