Chvilevaite
| Chvilevaite | |
|---|---|
| General | |
| Category | Sulfide mineral |
| Formula | Na(Cu,Fe,Zn)2S4 or Na(Cu,Fe,Zn)2S2 |
| IMA symbol | Cvi |
| Strunz classification | 2.FB.10 |
| Crystal system | Trigonal |
| Crystal class | Sulfide |
| Identification | |
| Color | bronze when freshly chipped, gradually blackening to sooty |
| Crystal habit | in the form of free grains and small aggregates |
| Cleavage | Perfect on {0001} |
| Fracture | irregular to uneven |
| Mohs scale hardness | 3 |
| Luster | metallic |
| Diaphaneity | opaque |
| Density | 3.94 (calculated) |
| Pleochroism | distinct, from pale orange to dark gray with a lilac tint. |
Chvilevaite (Russian: чвилеваи́т, чвилёваи́т, in its own name) is a rare hydrothermal polymetallic mineral from the class of complex sulfides, forming microscopic grains in related minerals, its composition is a rare combination of alkali (combining lithophile) and chalcophile metals — sodium ferro-sulfide, zinc and copper with the calculation formula Na(Cu,Fe,Zn)2S4, originally published and confirmed as Na(Cu,Fe,Zn)2S2.
The new mineral was studied, described and identified in 1985-1986 and named in honor of Tatyana Chvileva, a leading employee of the Institute of Mineralogy, Geochemistry and Crystal Chemistry of Rare Elements, a mineralogist at the Mineragraphy Cabinet.