Trevorite , Népouite Locality: Musongati (Musongoti; Colline Musongati), Rutana Province, Burundi Dimensions: 6.2 cm × 3.6 cm × 2.4 cm Trevorite is a very rare iron-rich Spinel Group species and garnierite is a synonym of nepouite, a rare Serpentine Group species. This very rare combination piece is certainly from a most obscure locale and country - Burundi. Musongati is a nickel, cobalt, copper lateritic deposit over a flat-lying, layered intrusion of gabbro, norite, and other mafic-ultramafic rocks (MINDAT). Pale green nepouite appears to be far richer on this specimen, than the black with a green or brown tint trevorite. It's hard to distinquish the two. There are also crusts of a splendent metallic mineral. The colors are far brighter on the back edge of the piece. Probably older material, but no proof. Ex. Jacques Montandon Collection. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Trevorite
A rare black nickel-iron spinel — the nickel member of the magnetite series.
Intro adapted from Wikipedia (CC BY-SA).
Trevorite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula NiFe³⁺₂O₄.
It crystallizes in the cubic crystal system (space group Fd-3m). It is a member of the Spinel structural group.
Key properties: Mohs hardness 5; specific gravity 5.164; Brown streak; Metallic luster.
IMA symbol Trv, grandfathered status — known before the IMA’s founding, named in 1921.
Found in a small tabular body of nickeliferous serpentinite, probably a contact deposit, along the junction of quartzite and an ultramafic intrusive (Bon Accord, South Africa).
It is found associated with Nimite, willemseite, nickeloan talc, violarite, millerite, reevesite, goethite (Bon Accord, South Africa); nickel, heazlewoodite, millerite (Mt. Clifford.
The mineral was named to honor Major Tudor Gruffydd Trevor (1865–1958), Welsh–South African geologist, Mining Inspector for the Pretoria district, Transvaal, South Africa.