White globular aggregate of the very rare Mg borate halurgite from the type and only known locality worldwide: Chelkar Salt Dome, Aksai Valley, Shalkar, Aktobe Province, Kazakhstan. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Halurgite
Halurgite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Mg₄[B₈O₁₃(OH)₂]₂·7H₂O.
Key properties: Mohs hardness 2.5–3; specific gravity 2.19; [Subvitreous.] luster; optically biaxial.
IMA symbol Hlg, IMA status: approved, named in 1962.
Of rare occurrence in interstices and vugs in a rock salt diapir.
It is found associated with Boracite, kaliborite, pinnoite, hilgardite, ginorite, bischofite, kieserite, preobrazhenskite, aksaite, strontioborite, metaborite, anhydrite, halite.
The mineral was named to honor the Institute of Halurgy, St. Petersburg, Russia, for its studies of saline deposits.