Guérinite
Guérinite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Ca₅(AsO₃OH)₂(AsO₄)₂·9H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 1.5; specific gravity 2.68–2.76; Vitreous to pearly luster; optically biaxial.
IMA symbol Gué, IMA status: approved, named in 1961.
A recent weathering product in oxidizing arsenic-rich mineral deposits.
It is found associated with Realgar, erythrite, quartz, calcite.
The mineral was named to honor Henri Guérin (1906–), who synthesized the compound.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
Browse more G minerals or help write this entry.