Umohoite , Calcurmolite Locality: Rabejac, Lodève , Hérault , Languedoc-Roussillon , France ( Locality at mindat.org ) Size: 12.5 x 8.6 x 3.3 cm. A significant specimen from a major French find of some years back, generally considered to have produced the finest specimens of the species (I am told). Both species here are extremely rare and this is the first I have had of either one. This large plate features a very large deposit of umohoite in rich concentration on the top of the specimen. Hundreds of crystal clusters of Calcurmolite surround it. From the prominent radioactive mineral collection of Alain Caubel, of France. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Calcurmolite
Calcurmolite is an IMA-recognized mineral species in the molybdate class, with the chemical formula (Ca₁₋ₓNaₓ)₂(UO₂)₃(MoO₄)₂(OH)₆₋ₓ·nH₂O.
It crystallizes in the monoclinic crystal system.
Key properties: Mohs hardness 2–3; optically biaxial.
IMA symbol Cau, IMA status: approved, named in 1959.
Found as a secondary mineral in the lower oxidized zone of Mo–U deposits.
It is found associated with Uraninite, uranophane, uranospinite, halloysite, betpakdalite, jarosite, ferrimolybdite (Kadzharan deposit, Armenia); umohoite, uranophane (Rabéjac deposit.
The name refers to its essential chemical components: CALCium, URanium, and MOLybdenum.