Dark red nabiasite crystals in a matrix of hausmannite from the famous Gambatesa mine in Italy. Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Nabiasite
Nabiasite is an IMA-recognized mineral species in the vanadate class, with the chemical formula BaMn₉(VO₄)₆(OH)₂.
It crystallizes in the cubic crystal system (space group Pa3).
Key properties: Mohs hardness 5; specific gravity 2; Dark yellow, almost orange streak; Vitreous luster; optically isotropic.
IMA symbol Nbi, IMA status: approved, named in 1997.
Found in an upper-greenschist-facies metamorphosed syn-sedimentary exhalative Mn deposit in radiolarian cherts along veinlets mineralized by hydrothermal remobilization.
It is found associated with Rhodochrosite, barite, friedelite, quartz.
The name refers to the hamlet of Nabias near the deposit.