Several orange single crystals of the very rare mineral zirconium mineral zircosulfate from the type and only known locality worldwide in Russia (Korgeredaba Massif, Sangilen Upland, Tuva Republic, Russian Federation) in a capsule. Very old find of 1966! Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Zircosulfate
Zircosulfate is an IMA-recognized mineral species in the sulfate class, with the chemical formula Zr(SO₄)₂·4H₂O.
It crystallizes in the orthorhombic crystal system (space group Fddd).
Key properties: Mohs hardness 2.5–3; specific gravity 2.85; Dull luster; optically biaxial.
IMA symbol Zrs, IMA status: approved, named in 1965.
Found in a cavity in intensely hydrothermally altered nepheline syenite pegmatite, perhaps formed by acid sulfatic solutions attacking eudialyte.
It is found associated with Hisingerite, smithsonite, “limonite”.
The name refers to zirconium and sulfate in its composition.