Neighborite from Poudrette quarry (Demix quarry; Uni-Mix quarry; Desourdy quarry; Carrière Mont Saint-Hilaire), Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada — Photo: Modris Baum · CC0
Neighborite
A sodium-magnesium double fluoride found as pink-brown rounded grains in Utah's Green River Formation.
Intro adapted from Wikipedia (CC BY-SA).
Neighborite is an IMA-recognized mineral species in the halide class, with the chemical formula NaMgF₃.
It crystallizes in the orthorhombic crystal system (space group Pbnm). It is a member of the Perovskite structural group.
Key properties: Mohs hardness 4.5; specific gravity 3.03; Vitreous to dull, greasy luster.
IMA symbol Nbo, IMA status: approved, named in 1961.
An authigenic mineral, formed under aluminum-deficient conditions in dolomitic oil shale (South Ouray, Utah, USA); in metamorphosed tuff and clayey carbonate sediments (Ural Mountains, Russia).
It is found associated with Burbankite, nahcolite, wurtzite, barytocalcite, garrelsite, pyrite, calcite, quartz (South Ouray, Utah, USA); quartz, aegirine, rhodochrosite, zircon.
The mineral was named to honor Frank Neighbor, district geologist of Sun Oil Co., Salt Lake City, Utah, USA, for his assistance in providing samples.