Formula: Cu₂ZnSnS₄

Species: Sulfides

Colour: Greenish black

Lustre: Metallic

Hardness: 4½

Crystal System: Tetragonal

Member of: Stannite Group. The zinc analogue of ferrokësterite.

Name: First described as “Silver-zinc stannite” in 1948. Named by V.N. Soboleva in 1956 as kësterite, after the discovery locality Këster (Kester; Кестёр) deposit, Arga-Ynnakh-Khai granite massif, Yakutia, Eastern-Siberian Region, Russia.

Type Locality: Kester deposit, Kester harpolith, Arga-Ynnakh-Khaya granite Massif, Yana-Adycha Region, Yana River Basin, Verkhoyansk District, Sakha, Russia