Stannite is a relatively rare tin ore mineral. It has composition Cu2FeS4Sn (so it is smetimes called tin pyrite). This specimen contains dark gray-black dense fine grained stannite showing a metallic luster, typical for the mineral. Unfortunately, there are other minerals that appear quite similar, so distinguishing stannite without a chemical analysis is difficult. Quartz and pyrite are also present in this specimen. It is 8 cm across. — Photo: Darla Sondrol · CC0
Stannite
A copper-iron-tin sulfide — the iron-rich partner of kesterite — a minor tin ore.
Intro adapted from Wikipedia (CC BY-SA).
Stannite is an IMA-recognized mineral species in the sulfide class, with the chemical formula Cu₂FeSnS₄.
It crystallizes in the tetragonal crystal system (space group I-42m). It is a member of the Sphalerite, Stannite structural group.
Key properties: Mohs hardness 4; specific gravity 4.3–4.5; Blackish streak; Metallic luster.
IMA symbol Stn, grandfathered status — known before the IMA’s founding, named in 1832.
Found in tin-bearing vein deposits of hydrothermal origin.
It is found associated with Chalcopyrite, sphalerite, tetrahedrite, arsenopyrite, pyrite, cassiterite, wolframite.
The name comes from the Latin stannum, tin.