Alwilkinsite-(Y)
Alwilkinsite-(Y) is an IMA-recognized mineral species in the sulfate class, with the chemical formula Y(UO₂)₃(SO₄)₂O(OH)₃(H₂O)₇·7H₂O.
It crystallizes in the orthorhombic crystal system (space group P2_12_12_1).
Key properties: Mohs hardness 2–2.5; specific gravity 3.371; Pale yellow-green streak; Vitreous luster; optically biaxial.
IMA symbol Alw-Y, IMA status: approved, named in 2015.
A secondary phase formed at ambient temperature by evaporative processes at moderately high relative humidity at the surface of a rock with high relative porosity and in an environment that was relatively oxidizing and generally acidic.
It is found associated with Calcite, dickite, gypsum, johannite, natrozippeite, zinczippeite.
The mineral was named to honor Alan (Al) J. Wilkins, MD (b. 1955), of Coto de Caza, California, for discovering the mineral.