What is Zircosulfate?
Zircosulfate is a rare white hydrated zirconium-titanium sulfate, known as a soft crust or powder from an alkaline massif where sulfate solutions altered zirconium-rich minerals.
Mineralogy and structure
Reference formula: (Zr,Ti)(SO4)2·4H2O. Zircosulfate is orthorhombic with the variable formula (Zr,Ti)(SO4)2·4H2O. It is a hydrated crust-forming mineral rather than a large-crystal jewellery material; no matching public COD CIF was selected for this batch. Zircosulfate is classified with sulfates and has orthorhombic crystal symmetry. Typical hardness is 2.5–3 on the Mohs scale and specific gravity is approximately 2.85–2.9.
Colour, lustre and habit
Typical colours include colourless, white. The usual crusty, powdery, massive habit and dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Zircosulfate forms in or is associated with acid sulfate alteration of zirconium-rich alkaline rocks and weathered sulfide-bearing pegmatites. Important documented localities include the Korgeredaba alkaline massif in the Sangilen Upland of Tuva, Russia.
A rare white crust from an alkaline massif
Zircosulfate is valuable because it is specific: a documented Tuva crust records an unusual alteration pathway and offers collectors a specimen story that cannot be reproduced by a generic white sulfate.
Collecting and care
Extremely soft and hydrated: keep dry and sealed, avoid acids, heat, water and dust, and preserve the original crust and locality label.
