Outstanding metallic acicular crystals of the very rare sulphosalt mineral giessenite from Japan (Otome Mine, Kimpuzan District, Honshu Island). Giesenite has its type locality in Giessen, mineral locality very close to the famous Lengenbach deposit. Ex.Dr.Hartel specimen. — Photo: David Hospital · CC BY-SA 4.0
Giessenite
Giessenite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula (Cu,Fe)₂Pb₂₆.₄(Bi,Sb)₁₉.₆S₅₇.
It crystallizes in the monoclinic crystal system (space group P2_12_12_1). It is a member of the Kobellite structural group.
Key properties: Mohs hardness 2.5; specific gravity 7.45; Grayish black streak; Metallic. R1 –R2: n.d luster.
IMA symbol Gie, IMA status: approved, named in 1963.
Of hydrothermal origin, with other sulfides.
It is found associated with Galena, pyrite, pyrrhotite, sphalerite, tennantite, seligmannite, geocronite, quartz, dolomite.
The name refers to Giessen, a village nearby the Binntal, Switzerland.