Sky blue crystals of the the new mineral rruffite (IMA 2009-077) on a contrasting matrix. Rruffite is a Ca-Cu arsenate. Rruffite has only been found in two localities worldwide! From: Jote Mine, Tierra Amarilla, Atacama Region, Chile. — Photo: David Hospital · CC BY-SA 4.0
Rruffite
Rruffite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Ca₂Cu(AsO₄)₂·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Roselite structural group.
Key properties: Mohs hardness 3; specific gravity 3.79; White streak; Vitreous luster; optically biaxial.
IMA symbol Ruf, IMA status: approved, named in 2009.
Secondary mineral in the oxidation zone of a Cu-As ore deposit.
It is found associated with Quartz, baryte, mansfieldite, alumopharmacosiderite, conichalcite, metazeunerite, barahonite-(Al).
The name refers to the RRUFF project, an Internet-based internally consistent and integrated database of Raman spectra, X-ray diffraction, and chemical data for minerals.