Ammoniolasalite
Ammoniolasalite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula [(NH₄)₂Mg₂(H₂O)₂₀]·[V₁₀O₂₈].
It crystallizes in the monoclinic crystal system (space group C2/c). It is a member of the Pascoite structural group.
Key properties: Mohs hardness 1; specific gravity 2.82; Light orange streak; Vitreous luster; optically biaxial.
IMA symbol Alas, IMA status: approved, named in 2018.
Product of postmining oxidation of primary montroseite-corvusite assemblages at ambient temperatures. The ammonium derived from organic matter. In a bedded or roll-front U and V deposit in sandstone containing carbonaceous plant material.
It is found associated with Ammoniozippeite, schindlerite, wernerbaurite.
Ammonio for the composition as the NH4-dominant (over Na) analogue of lasalite.