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
Bobcookite
Bobcookite is an IMA-recognized mineral species in the sulfate class, with the chemical formula NaAl(UO₂)₂(SO₄)₄·18H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 2.5; specific gravity 2.669; Very pale yellowish green streak; Vitreous luster; optically biaxial.
IMA symbol Bbc, IMA status: approved, named in 2014.
Occurs as efflorescent crusts, on the surfaces of mine walls, derived from the oxidation of primary minerals (uraninite, pyrite, chalcopyrite, bornite and covellite) in a relatively humid underground environment.
It is found associated with Wetherillite, boyleite, chalcanthite, dietrichite, gypsum, hexahydrite, johannite, pickeringite, rozenite.
The mineral was named to honor Robert (Bob) B. Cook (b. 1944), Professor Emeritus, Department of Geology and Geography, Auburn University, Auburn, Alabama, USA.