Pale brown crystals and crystal aggregates of the very rare mineral manganosegelerite from the type and only known locality worldwide: Vasin-Myl'k Mountain, Kola, Russian Federation. — Photo: David Hospital · CC BY-SA 4.0
Manganosegelerite
Manganosegelerite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Mn²⁺₂Fe³⁺(PO₄)₂(OH)·4H₂O.
It crystallizes in the orthorhombic crystal system (space group Pbca). It is a member of the Overite structural group.
Key properties: Mohs hardness 3–4; specific gravity 2.76; Yellow streak; Vitreous luster; optically biaxial.
IMA symbol Msgl, IMA status: approved, named in 1984.
Found in fractures in granite pegmatite.
It is found associated with Mitridatite, lun’okite, eosphorite, kingsmountite, manganoan gordonite.
As the manganese analog of segelerite.