RENARDITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Uranyl phosphates
    Crystal system : Orthorhombic
    Chemistry : Pb(UO2)4(PO4)2(OH)4 7H2O
    Rarity : Rare to very rare

Renardite (also called dewindtite) is a relatively rare secondary phosphate from the oxidation zone of uranium deposits. It belongs structurally to the phosphuranylite group. It was named in honor of Professor Alphonse François Renard of the University of Ghent (Belgium). Foxrite occurs as elongated and flattened lamellar crystals measuring up to 2 mm, frequently grouped in rosettes or divergent aggregates. It is not fluorescent under ultraviolet light. Transparent to translucent, its color is lemon yellow to amber yellow, rarely brownish. It is frequently associated with phosphuranylite and parsonsite. It is a very minor ore of uranium.

Main photo : Renardite from Shinkolobwe, Katanga, Democratic Republic of Congo © Uwe Haubenreisser

Renardite in the World

We encounter the renardite in good crystal groups and in millimetric incrustations at Shinkolobwe (Kasolo mine) and at Swambo in Congolese Katanga.

Right photo : Renardite and torbernite from Shinkolobwe, Katanga, Democratic Republic of Congo © Carsten Slotta

Renardite in France

French uranium deposits have produced some of the finest specimens in the world. The small Kerségalec mine near Lignol (Morbihan) is the best French site : renardite occurred there in feltings consisting of a multitude of elongated tabular crystals, or in centimetric arborescent torbernite pseudomorphs. Very good veneers of millimetric crystals are known at Lachaux (Puy-de-Dôme), and crystals implanted on ianthinite as well as rosette aggregates come from Bois Noirs (Limouzat, Loire).

Twinning

No known twinning for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 3
Density : 4.0
Fracture : Undeterminated
Streak : Yellow

TP : Translucent
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : Very strong