Alfredopetrovite , Ahlfeldite , Chalcomenite Locality: El Dragón Mine, Quijarro Province, Potosi Department, Bolivia Size: 1.3 cm × 0.7 cm × 0.8 cm Description: Druse of tiny alfredopetrovite crystals, colorless to greyish tone, coating over blue chalcomenite and pink ahlfeldite. Some areas, with no colored background minerals, let us to see perfectly crystals. You can also observe face reflections of this extremely rare species. Alfredopetrovite is the first aluminium selenite mineral. On a kruťait-penroseite matrix. — Photo: Joan Rosell , from rosellminerals.com · CC BY-SA 4.0
Alfredopetrovite
Alfredopetrovite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Al₂(Se⁴⁺O₃)₃·6H₂O.
It crystallizes in the hexagonal crystal system (space group P-62c).
Key properties: Mohs hardness 2.5; specific gravity 2.504; White streak; Vitreous luster; optically uniaxial.
IMA symbol Afd, IMA status: approved, named in 2015.
Found as a secondary mineral in the weathered portions of a telethermal vein hosted by sandstones and shales.
It is found associated with Ahlfeldite, allophane, calcite, chalcomenite, favreauite, felsőbányaite, malachite, molybdomenite.
The mineral was named to honor Alfredo Petrov (b. 1955), geologist.