Greenish blue fuettererite aggregates of this extremely rare and relatively new tellurium mineral (IMA 2011-111) from Bird Nest mine (Bird Nest drift, Otto Mountain, Baker, Soda Mountains, San Bernardino County, California, United States of America). — Photo: David Hospital · CC BY-SA 4.0
Fuettererite
Fuettererite is an IMA-recognized mineral species in the halide class, with the chemical formula Pb₃Cu²⁺₆Te⁶⁺O₆(OH)₇Cl₅.
It crystallizes in the hexagonal crystal system (space group R-3).
Key properties: Mohs hardness 2–3; specific gravity 5.552; Pale bluish green streak; Adamantine luster; optically uniaxial.
IMA symbol Fue, IMA status: approved, named in 2011.
A secondary phase formed by partial oxidation of tellurides, chalcopyrite and galena in quartz veins.
It is found associated with Br-rich chlorargyrite, iodargyrite, telluroperite (association 1); paratacamite, anglesite, anatacamite, atacamite, chalcopyrite, galena, goethite, hematite.
The mineral was named to honor Otto Fuetterer (1880-1970), who is largely responsible for the development of the mining claims on Otto Mountain.