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
Rietveldite
Rietveldite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Fe(UO₂)(SO₄)₂(H₂O)₅.
It crystallizes in the orthorhombic crystal system (space group Pmn2_1). It is a member of the Svornostite structural group.
Key properties: Mohs hardness 2; specific gravity 3.31; White streak; Vitreous luster; optically biaxial.
IMA symbol Rvd, IMA status: approved, named in 2016.
A result of oxidation in a humid, postmining, underground environment, attacking disseminations of uraninite and pyrite originally deposited as replacements of wood and other organic material in permeable sandstone (Utah).
It is found associated with Asphaltum, ferricopiapite, gypsum, römerite, shumwayite, halotrichite (Utah); halotrichite, krausite, melanterite, native sulfur, voltaite (Germany); rozenite.
The mineral was named to honor Dutch crystallographer Hugo M. Rietveld (1932-2016) the author of the Rietveld method for the refinement of neutron and powder X-ray diffraction data.