Single crystal aggregate of the rare molybdenum mineral melkovite from the type locality: U-Mo Occurrence, Shunak Mountains, Karaganda Oblast, Kazakhstan. — Photo: David Hospital · CC BY-SA 4.0
Melkovite
Melkovite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CaFe³⁺₂Mo₅O₁₀(PO₄)₂(OH)₁₂·8H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Betpakdalite structural group.
Key properties: Mohs hardness 3; specific gravity 2.97; Dull to waxy luster; optically biaxial.
IMA symbol Mko, IMA status: approved, named in 1968.
Localized along joints in sandstone, produced through alteration of molybdenite in the oxidized zone of small molybdenite-fluorite deposits.
It is found associated with Fluorite, molybdenite, magnetite, powellite, ferrimolybdite, iriginite, jarosite.
The mineral was named to honor Professor Vyacheslav Gavrilovich Melkov (1911-1991), Russian mineralogist specializing in uranium minerals, of the All-Union Research Institute of Mineral Resources.