Khaidarkanite Locality: Mednaya Gorka, Khaidarkan (Chaidarkan) Sb-Hg deposit, Fergana Valley , Alai (Alay) Range, Osh Oblast , Kyrgyzstan ( Locality at mindat.org ) An extremely rich and colorful specimen! Large piece for the species, to date. 6 x 4 x 2.5 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Khaidarkanite
Khaidarkanite is an IMA-recognized mineral species in the halide class, with the chemical formula Cu₄Al₃(OH)₁₄F₃·2H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Cyanotrichite structural group.
Key properties: Mohs hardness 2.5; specific gravity 2.84; Light blue streak; Vitreous luster; optically biaxial.
IMA symbol Kdk, IMA status: approved, named in 1998.
Secondary in highly oxidized, copper-bearing, fluorite-rich veinstone that locally evolved small quantities of hydrofluoric acid (HF) during weathering (Great Sled Dale).
It is found associated with Calcite, quartz, baryte, fluorite, malachite, Cu-allophane, conichalcite, chrysocolla, an Al-fluorhydroxide.
The name is derived from the locality from which the first samples were collected.