Well formed bronze colored crystal of the extremely rare sinnerite. Sinnerite is only found in two localities worldwide and Lengenbach is the type locality. Find of 1995. The number of confirmed sinnerite specimens from Lengenbach was only 19 until 2002 and this number later grew to only 32 (!) in 2008, so it is a real rarity !!. (Faszination Lengenbach book, 2008). — Photo: David Hospital · CC BY-SA 4.0
Sinnerite
Sinnerite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Cu₆As₄S₉.
It crystallizes in the triclinic crystal system (space group P1).
Key properties: Mohs hardness 4; specific gravity 5.2; Gray-black streak; Metallic. R1-R2: n.d luster.
IMA symbol Sin, IMA status: approved, named in 1964.
On sulfides in crystalline dolostone.
It is found associated with Realgar, coloradoite, tennantite, galena, sphalerite.
The mineral was named to honor Rudolph von Sinner (1890-1960), President of the Commission of the Natural History Museum, Bern, Switzerland.