Pääkkönenite
A metallic-gray antimony-arsenic sulfide named for Finnish geologist Veikko Pääkkönen.
Intro adapted from Wikipedia (CC BY-SA).
Pääkkönenite is an IMA-recognized mineral species in the sulfide class, with the chemical formula Sb₂AsS₂.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Stibnite structural group.
Key properties: Mohs hardness 2; specific gravity 5.21; Gray with a brownish tint streak; Metallic luster.
IMA symbol Pä, IMA status: approved, named in 1980.
Found in hydrothermal mineral deposits with other Sb–As-bearing minerals.
It is found associated with Arsenopyrite, arsenic, löllingite, stibnite, antimony (Kalliosalo deposit, Finland); stibarsen, arsenic, stibnite, sphalerite, siderite, quartz (Přı́bram.
The mineral was named to honor Viekko Pääkkönen (1907–1980), Finnish geologist, who studied the ore deposits of the type region.