Outstanding specimen of the extremely rare mineral hashemite from one of the only three known localities worldwide: Lisdan-Siwaga Fault, Hashem Region, Amman, Jordan. Hashemite is a barium chromate and is one of only three minerals with essential Ba and Cr in its chemical composition, with hawthorneite and redledgeite being the others. Ex Vandenbroucke Museum collection specimen, from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Hashemite
A very rare barium chromate — the barium analogue of tarapacáite — from Jordan's Hatrurim rocks.
Intro adapted from Wikipedia (CC BY-SA).
Hashemite is an IMA-recognized mineral species in the chromate class, with the chemical formula Ba(CrO₄).
It crystallizes in the orthorhombic crystal system (space group Pnma). It is a member of the Baryte structural group.
Key properties: Mohs hardness 3.5; specific gravity 4.54–4.59; Adamantine luster; optically biaxial.
IMA symbol Hsh, IMA status: approved, named in 1978.
Disseminated in veinlets cutting phosphate carbonate rock, the stratigraphic correlative of the Mottled Zone of the Hatrurim Formation, Israel.
It is found associated with Chromian ettringite, apatite, bultfonteinite, calcite.
The mineral was named to honor the Hashemite Kingdom of Jordan, within which the species occurs.