Fourmarierite - Encyclopedia

    Class : Oxides and hydroxides
    Subclass : Uranyl hydroxides
    Crystal system : Orthorhombic
    Chemistry : Pb(UO₂)₄O₃(OH)₄ 4H₂O
    Rarity : Rare

Fourmarierite is one of seven currently known mixed oxides of uranium and lead. When they are dominant, these minerals mark the oxidized layers which coat the residual pitchblende with their orange to red color, hence their generic name "orange gummite". It was named in honor of the Belgian geologist Paul Fourmarier, professor at the University of Liège. Fourmarierite is carmine red to orange-red in color, rarely orange, and forms small elongated tabular crystals with pseudohexagonal outlines, sometimes acicular crystals. It also exists in small compact cryptocrystalline masses. It associates with other uranium oxides (kasolite, billietite, curite, becquerelite, etc...) in zones of pitchblende alteration.

Main photo : Fourmarierite from Shinkolobwe Mine, Kambove, Haut-Katanga, D. R. of Congo © Jason B. Smith

No twin known for this mineral species.

No fakes recorded for this mineral species.