User:Tillman/Francevillite

Yellow curienite on bright orange francevillite, both at their type locality, the Mounana uranium mine, near Franceville. Specimen size: 7.7 x 6.4 x 3.7 cm.

Francevillite is a secondary uranium mineral formed by alteration of earlier uranium minerals, such as uraninite. Francevillite is a uranyl-group vanadate in the Tyuyamunite series. Its empirical formula is (Ba,Pb)(UO₂)₂V₂O₈ · 5(H₂O). Francevillite is a strongly radioactive mineral.

Francevillite is named after Franceville, Haut-Ogooué, Gabon. Its type locality is the idle Mounana uranium mine, near Franceville.

Franceville is typically orange or brownish yellow. At its type locality at the Mounana mine, it is associated with curienite, chevetite (a lead vanadate), & mounanaite (another lead vanadate).

References

• Francevillite at Uranium and Thorium Minerals of the World
• Francevillite Mineral Data at webmineral
• Francevillite at Mindat.org

{{Oxide-mineral-stub [[Category:Uranium minerals [[Category:Vanadate minerals