Metavariscite Locality: Lucin District, Pilot Range , Box Elder County , Utah , USA ( Locality at mindat.org ) A rare hydrated aluminum phosphate, closely-related to its much more common cousin variscite (and similar in appearance) but with a different atomic structure. 3.7 x 2.9 x 1.8 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Metavariscite
Metavariscite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Al(PO₄)·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n). It is a member of the Phosphosiderite structural group.
Key properties: Mohs hardness 3.5; specific gravity 2.51–2.54; White streak; Vitreous luster; optically biaxial.
IMA symbol Mvar, IMA status: approved, named in 1925.
Commonly a product of weathering phosphatic rocks; can form as concretions by the phosphatization of kaolin during weathering; probably a reaction product of phosphate fertilizer in acid soil.
It is found associated with Variscite.
The name refers to the dimorphous relation with variscite.