Rietveldite , Bobcookite , Ferricopiapite (Field of view 2,2 mm)) Locality: Giveway-Simplot Mine, Red Canyon, White Canyon District, San Juan Co., Utah, USA Original description: Light brownish yellow sprays of rietveldite intergrown with yellow ferricopiapite, and rounded green hygroscopic bobcookite. White spheres are an unidentified sulfate, possibly tamarugite. FOV = 2.2 mm. Collected 2007 — Photo: Travis A. Olds · CC BY-SA 3.0
Ferricopiapite
Ferricopiapite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Fe³⁺₀.₆₇Fe³⁺₄(SO₄)₆(OH)₂·20H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Copiapite structural group.
Key properties: Mohs hardness 2; specific gravity 2.14; optically biaxial.
IMA symbol Fcpi, grandfathered status — known before the IMA’s founding, named in 1939.
A secondary mineral formed typically by the weathering and oxidation of iron sulfide in a wide range of rock types, preserved in arid climates.
It is found associated with Pyrite.
The name refers to the ferric iron member of the copiapite group.