Composition: Pb(UO2)SiO4.H2O
Crystal System : Monoclinic
Colours: Yellow, yellow-brown, red-orange, grey
Lustre : Adamantine, greasy, dull, earthy
Hardness (H) : 4.5
Specific Gravity (S.G) : 5.83-6.50


Extremely rare. Reported from outcrop (Gebhard, 1999), and probably occurs in the second oxidation zone also.


  • Supergene
  • 1st Oxidation Zone
  • 2nd Oxidation Zone

Notable Finds

As tiny orange crystals on linarite, found at outcrop.

Paragenetic and General Notes

One of only two uranium minerals reported from Tsumeb. (The other is metazeunerite.)

Kasolite occurs as tiny orange crystals on linarite, found at outcrop (Gebhard, 1999). 

In a discussion of newly discovered minerals and implicitly from the second oxidation zone, Keller and Bartelke (1982) describe prismatic crystals of kasolite to 2 mm, commonly coated by goethite and associated with arsendescloizite, mimetite and willemite.