Outstanding colorless platy crystals of the extremely rare mineral clinokurchatovite from the type locality (Sayak, Karaganda Oblast, Kazakhstan) and only one of the two known localities worldwide. Holotype material. Ex.Dr.Hartel collection. — Photo: David Hospital · CC BY-SA 4.0
Clinokurchatovite
Clinokurchatovite is an IMA-recognized mineral species in the borate class, with the chemical formula CaMgB₂O₅.
It crystallizes in the monoclinic crystal system (space group P2_1/b).
Key properties: Mohs hardness 4.5; specific gravity 3.07–3.08; optically biaxial.
IMA symbol Ckht, IMA status: approved, named in 1982.
A replacement of kurchatovite in boron-bearing rocks.
It is found associated with Kurchatovite, suanite, ludwigite, szaibélyite, sakhaite, clinohumite, svabite, sphalerite (Solongo deposit, Russia).
As the monoclinic dimorph of kurchatovite.