Outstanding yellow crystals of the very rare mineral norsethite, from Rosh Pinah Mine, Oranjemund, Karas Region, Namibia. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Norsethite
Norsethite is an IMA-recognized mineral species in the carbonate class, with the chemical formula BaMg(CO₃)₂.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Calcite-Dolomite structural group.
Key properties: Mohs hardness 3.5; specific gravity 3.837; Vitreous luster; optically uniaxial.
IMA symbol Nst, IMA status: approved, named in 1961.
A rare authigenic mineral in and underlying the Green River Formation; a primary mineral in carbonatites; uncommon in metamorphosed hydrothermal mineral deposits.
It is found associated with Shortite, labuntsovite, searlesite, northupite, loughlinite, barytocalcite, witherite, pyrite, quartz (Westvaco trona mine, Wyoming, USA).
The mineral was named to honor Keith Norseth (1927–1991), American engineering geologist, Westvaco trona mine, Wyoming, USA, for his assistance in mineralogical studies.