Really outstanding and very rich specimen of the very rare janchevite (IMA2017-079) from the famous Kombat deposit in Namibia. Dozens of crystals are present in the sample. Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Janchevite
Janchevite is an IMA-recognized mineral species in the halide class, with the chemical formula Pb₇V⁵⁺(O₈.₅ ₀.₅)Cl₂.
It crystallizes in the tetragonal crystal system (space group I4/mmm). It is a member of the Asisite structural group.
Key properties: Mohs hardness 2.5; specific gravity 8.16; Orange streak; Adamantine luster.
IMA symbol Jan, IMA status: approved, named in 2017.
A product of the regional metamorphism of a Pb-Mn-(As-Ba)-rich, chemically heterogeneous, volcanic-hydrothermal assemblage.
It is found associated with Barite, hausmannite, calcite, magnesite, kombatite.
The mineral was named to honor Macedonian mineralogist Simeon Janchev (b. 1942), a specialist in the mineralogy and petrology of igneous rocks and metasomatic ore deposits.