Editorial Feature

Balyakinite – Occurrence, Properties, and Distribution

Jun 13 2014

Balyakinite was named to honor Tatyana Stepanovna Balyakina (1906–1986), Geology Instructor, Moscow University in Moscow, Russia.

Properties of Balyakinite

The following are the key properties of balyakinite:

Cell Data
- Space group: Pmcn
- a = 7.604(6)
- b = 5.837(4)
- c = 12.705(6)
- Z = 8

Crystal Data
- Orthorhombic
- Point group: 2/m2/m2/m
- As minute short prismatic crystals, and as grains, to 0.5mm
- X-ray powder pattern: 2.85 (10), 2.84 (8), 3.09 (5), 1.711 (5), 4.34 (4), 3.18 (4), 2.28 (3.5)

Chemical Composition

Elements	Content 1	Content 2
TeO₂	67.54	66.74
CuO	33.42	33.26
Sb₂O₃	1.12	-
PbO	0.62	-
Ag₂O	0.26	-
FeO	0.08	-
SeO₂	0.03	-
Total	103.07	100.00

Optical Properties
- Anisotropism: Slight
- Optical class: Biaxial (-)
- Pleochroism: Weak; in greens
- Orientation: X = a; Y = b; Z = c
- α = 2.11; β = 2.18; γ = 2.22
- 2V(meas.) = >80°

Estimated Properties

Electron density	Bulk density (electron density) = 4.96 g/cm³ note: Specific gravity of balyakinite = 5.65 g/cm³
Photoelectric	PE_Balyakinite = 199.17 barns/electron U = PE_Balyakinite x ρ electron density = 988.16 barns/cm³
Fermion index	Fermion index = 0.04 Boson index = 0.96
Radioactivity	Balyakinite is not radioactive

How to Identify Balyakinite

Balyakinite can be identified in the field by its color variations, such as blue-green, and gray-green. This mineral has a light blue-green streak.

The density of balyakinite is 5.64 g/cm³, with a hardness of 3.5 – approximate to a copper penny.

Global Distribution

Balyakinite is distributed mainly in Russia, from the Pionersk deposit, eastern Sayan, and the Aginsk goldtelluride deposit, Kamchatka, Far Eastern Region.