Chinleite-(Y)
Chinleite-(Y) is an IMA-recognized mineral species in the sulfate class, with the chemical formula NaY(SO₄)₂·H₂O.
It crystallizes in the hexagonal crystal system (space group P3_221). It is a member of the Rhabdophane structural group.
Key properties: Mohs hardness 2.5–3; specific gravity 3.385; White streak; Vitreous luster; optically uniaxial.
IMA symbol Chi-Y, IMA status: approved, named in 2016.
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 Gypsum, hexahydrite, johannite, metauranospinite, natrojarosite.
The name refers to the Chinle Formation of Upper Triassic age and a suffix for the dominant rare earth element, yttrium.