Rambergite Field of view 3 mm Locality: Garpenberg Norra Mine, Garpenberg, Hedemora, Dalarna County, Sweden — Photo: Leon Hupperichs · CC BY-SA 3.0
Rambergite
A manganese sulfide found in organic-rich anoxic sediments of the Baltic and in Swedish skarn.
Intro adapted from Wikipedia (CC BY-SA).
Rambergite is an IMA-recognized mineral species in the sulfide class, with the chemical formula MnS.
It crystallizes in the hexagonal crystal system (space group P6_3mc). It is a member of the Wurtzite structural group.
Key properties: Mohs hardness 4; Brown streak; Vitreous to resinous luster; optically uniaxial.
IMA symbol Rbg, IMA status: approved, named in 1995.
From tremolite skarn, likely a later stage hydrothermal mineral under low temperature conditions (Sweden). In metasedimentary manganese deposits (Japan). In anoxic laminated marine sediments (Gotland Deep, Baltic Sea).
The mineral was named to honor Norwegian-Swedish geologist Hans Ramberg (1917-1998), former professor of mineralogy and petrology, Uppsala University, Sweden.