Chervetite with Francevillite

Unknown Owner

A very choice example for this rare species with lustrous crystals measuring to 0.5 cm in length across the top of matrix with yellow francevillite. In good condition.The Mounana Mine, located near Franceville in the Haut-Ogooue Province of Gabon, was a world-class uranium and vanadium deposit situated within the Paleoproterozoic Francevillian Basin. Geologically, the mineralization occurred in the sandstones of the Francevillian Series, where tectonic fracturing allowed for the concentration of uranium through both primary hydrothermal and extensive secondary supergene processes. This environment led to the discovery of several unique species, most notably chervetite, a lead vanadate, and francevillite, a hydrated barium lead uranyl vanadate, both of which have Mounana as their type locality. Historically, the deposit was discovered in 1956 by the Commissariat a l'Energie Atomique (CEA) and was operated by the Compagnie des Mines d'Uranium de Franceville (COMUF) from 1961 until its closure in 1999. During its nearly forty years of operation, the Mounana Mine was a vital source of uranium for France and remains a site of immense scientific importance due to its diverse and complex secondary mineralogy.