Sabugalite Locality: Margnac Mine, Compreignac , Haute-Vienne , Limousin , France ( Locality at mindat.org ) An extremely rare uranium phosphate, with crystals completely covering 4 of 6 sides and forming a solid specimen. This is very rich and colorful. 4.5 x 2.5 x 2 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Sabugalite
Sabugalite is an IMA-recognized mineral species in the phosphate class, with the chemical formula HAl(UO₂)₄(PO₄)₄·16H₂O.
It crystallizes in the tetragonal crystal system.
Key properties: Mohs hardness 2.5; specific gravity 3.2; Weakly vitreous luster; optically biaxial.
IMA symbol Sbg, grandfathered status — known before the IMA’s founding, named in 1951.
A secondary mineral formed in the oxidized zone of uranium veins.
It is found associated with Meta-autunite, saléeite, phosphuranylite.
The name refers to Sabugal Co., Portugal, in which the mineral was first found.