Hashemite is a very rare

barium Barium is a chemical element; it has symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. Th ...

chromate Chromate or chromat, and their derived terms, may refer to: Chemistry * Chromate and dichromate, ions * Monochromate, an ion * Trichromate, an ion * Tetrachromate, an ion * Chromate conversion coating, a method for passivating metals Biolog ...

mineral with the formula Ba(Cr,S)O4.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. It is a representative of natural chromates - a relatively small and rare group of minerals. Hashemite is the

-analogue of tarapacáite. It is also the

chromium Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

-analogue of

baryte Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate (Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), ...

, and belongs to the

baryte group Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate (Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), ...

of minerals. Hashemite is stoichiometrically similar to

crocoite Crocoite is a mineral consisting of lead chromate, Pb Cr O4, and crystallizing in the monoclinic crystal system. It is identical in composition with the artificial product chrome yellow used as a paint pigment. Description Crocoite is comm ...

and

chromatite Chromitite is an igneous cumulate rock composed mostly of the mineral chromite. It is found in layered intrusions such as the Bushveld Igneous Complex in South Africa, the Stillwater igneous complex in Montana and the Ring of Fire discovery in Ont ...

. Hashemite is

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic Lattice (group), lattices result from stretching a cubic crystal system, cubic lattice along two of its orthogonal pairs by two different factors, res ...

, with space group ''Pnma''. I was found together with

-bearing

ettringite Ettringite is a hydrous calcium aluminium sulfate mineral with formula: . It is a colorless to yellow mineral crystallizing in the trigonal crystal system, system. The prismatic crystals are typically colorless, turning white on partial dehydratio ...

and an

apatite group Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ion, respectively, in the crystal. The formula of the admixture of the three most common endm ...

mineral in the

Hatrurim Formation The Hatrurim Formation or Mottled Zone is a geologic formation with outcrops all around the Dead Sea Basin: in the Negev Desert in Israel, in the Judaean Desert on the West Bank, and in western Jordan. It includes late Cretaceous to Eocene aged im ...

, known for the occurrence of rocks formed due to natural

pyrometamorphism Pyrometamorphism is a type of metamorphism in which rocks are rapidly changed by heat, ''e.g.'' coming from a rapidly emplaced extrusive or intrusive igneous rock or from a fossil fuel fire. The rocks produced by pyrometamorphism include buchite, ...

. Hashemite is named after the Hashemite Kingdom of Jordan.

References

Chromate minerals Barium minerals Orthorhombic minerals Baryte group {{mineral-stub