Hashemite (mineral) explained

Hashemite
Category:Chromate minerals
Formula:Barium Chromate Ba(S,Cr)O4
System:Orthorhombic
Color:Brown to yellow
Cleavage:Perfect, good
Mohs:3.5
Luster:Adamantine
Gravity:4.54 - 4.59
Diaphaneity:Translucent

Hashemite is a very rare barium chromate mineral[1] with the formula Ba(Cr,S)O4.[2] It is a representative of natural chromates - a relatively small and rare group of minerals. Hashemite is the barium-analogue of tarapacáite. It is also the chromium-analogue of baryte, and belongs to the baryte group of minerals. Hashemite is stoichiometrically similar to crocoite and chromatite. Hashemite is orthorhombic, with space group Pnma. I was found together with chromium-bearing ettringite and an apatite group mineral in the Hatrurim Formation, known for the occurrence of rocks formed due to natural pyrometamorphism. Hashemite is named after the Hashemite Kingdom of Jordan.

Notes and References

  1. Web site: Hashemite: Hashemite mineral information and data . Mindat.org . 5 March 2016.
  2. Hauff, P.L., Foord, E.E., and Rosenblum, S., 1983. Hashemite, Ba(Cr,S)O4, a new mineral from Jordan. American Mineralogist 68, 1223-1225.