Formula: BaMg(CO3)2
Anhydrous normal carbonate, dolomite group,
barium-bearing mineral
Crystal System: Trigonal
Specific gravity: 3.84 measured, 3.84 calculated
Hardness: 3½
Streak: White
Colour: Colourless, cloudy white
Solubility: Insoluble in water but readily decomposed by cold dilute hydrochloric acid
Environments
Carbonatites
Metamorphic environments
Hydrothermal environments
Norsethite is a primary mineral in
carbonatites, and uncommon in metamorphosed hydrothermal
mineral deposits
(HOM).
Localities
At the Rosh Pinah Mine, Rosh Pinah, Oranjemund, ǁKaras Region, Namibia, norsethite has been found in large
quantities in a
zinc-lead-copper
deposit. It is one of the major gangue minerals of the deposit, is closely
associated with calcite and is apparently of hydrothermal origin. Associated
barium-bearing minerals include celsian,
baryte, barytocalcite and
benstonite
(AM 52.1770-1775).
The type locality is the Westvaco mine, Green River formation, Sweetwater county, Wyoming, USA. Here norsethite
was found in bentonite-hosted
dolomitic black oil shale below
the main trona bed, associated with
shortite, labuntsovite,
searlesite, loughlinite,
pyrite and quartz. It also occurs there
in grey shale with abundant shortite
and northupite, some searlesite
and loughlinite, in a fine-grained matrix consisting essentially of
quartz and pyrite. Norsethite
occurs as circular plates or flattened rhombohedral crystals, 0.2 to 2.0 mm across
(AM 46.420-429). Other associated minerals include witherite
northupite, leucosphenite
dolomite, calcite and
barytocalcite
(Mindat, HOM).
Back to Minerals