Green crystal aggregates of bario-olgite from Kola peninsula (Palitra Pegmatite, Karnasurt Mine, Kedykverpakhk Mountain, Murmansk Oblast, Russian Federation). Ex. Excalibur Mineral Company specimen. Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Bario-olgite
Bario-olgite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Na(Na,Sr,Ce)₂Ba(PO₄)₂.
It crystallizes in the hexagonal crystal system (space group P3). It is a member of the Aphthitalite structural group.
Key properties: Mohs hardness 4.5–5; specific gravity 3.986; White streak; Vitreous luster; optically uniaxial.
IMA symbol Bolg, IMA status: approved, named in 2003.
A late-stage crystallization product of a dry melt supersaturated in Na and F at temperatures of 300-350° C.
It is found associated with Intermixed with manaksite, natrosilite, villiaumite; also aegirine, analcime, chkalovite, natrolite, serandite, sodalite, ussingite, vuonnemite.
Bario for the dominant presence of barium in the composition and the relation to olgite.