Exhibition of Kostovite in the National Natural History Museum, Sofia, Bulgaria — Photo: Motekov · CC BY-SA 3.0
Kostovite
A rare gray-white orthorhombic gold-copper telluride.
Intro adapted from Wikipedia (CC BY-SA).
Kostovite is an IMA-recognized mineral species in the sulfide class, with the chemical formula AuCuTe₄.
Key properties: Mohs hardness 2–2.5; specific gravity 8.43; Metallic luster; optically biaxial.
IMA symbol Ktv, IMA status: approved, named in 1965.
From gold- and tellurium-bearing replacement copper deposits (Chelopech, Bulgaria; Campbell mine, Arizona, USA).
It is found associated with Kesterite, tellurium, chalcopyrite, tennantite, barite (Chelopech, Bulgaria); tellurium, hessite, sylvanite (Buckeye Gulch, Colorado, USA); tellurium, altaite.
The mineral was named to honor Professor Ivan Kostov (1913–), Bulgarian mineralogist, University of Sophia, Bulgaria.