Green crystals of th extremely rare copper tellurate mineral balyakinite from one of the only two known localities worldwide: Salmchâteau, Vielsalm, Luxembourg Province, Belgium. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Balyakinite
Balyakinite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu²⁺(Te⁴⁺O₃).
It crystallizes in the orthorhombic crystal system (space group Pmcn).
Key properties: specific gravity 5.6; Pale bluish green streak; optically biaxial.
IMA symbol Byk, IMA status: approved, named in 1980.
A rare mineral formed in the oxidation zone as an alteration product of Cu–Te sulfides.
It is found associated with Tetrahedrite, chalcopyrite, tellurite, bilibinskite, bogdanovite, teineite, quartz (Aginsk deposit, Russia).
The mineral was named to honor Tat’yana Stepanovna Balyakina (1906–1986), Geology Instructor, Moscow University, Moscow, Russia.