Outstanding metallic crystals of the extremely rare nickel selenide-telluride mineral kitkaite from the type and only known locality worldwide in Kitka River Valley (Kitka River Valley, Kuusamo, North Ostrobothnia, Finland) in a completely analyzed specimen by SEM/EDS. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Kitkaite
Kitkaite is an IMA-recognized mineral species in the sulfide class, with the chemical formula NiTeSe.
It crystallizes in the hexagonal crystal system (space group P-3m1). It is a member of the Melonite structural group.
Key properties: specific gravity 7.19; Metallic. Anisotropism: Distinct, from pale gray to pink or purple. R1 –R2: (400) 49.4–53.0, (420) 50.3–52.0 luster.
IMA symbol Kk, IMA status: approved, named in 1965.
Found in narrow carbonate-bearing fissure veinlets in albite.
It is found associated with Clausthalite, hematite, selenian polydymite, selenian linnaeite, pyrite.
The name refers to the Kitka River, Finland, in the valley of which the mineral was found.