Chemistry:Zhangpeishanite

From HandWiki
Short description: Halide mineral
Zhangpeishanite
General
CategoryMineral
Formula
(repeating unit)
BaFCl
Strunz classification3.DC.25
Dana classification9.2.11.3
Crystal systemTetragonal
Crystal classDitetragonal Dipyramidal
H-M symbol: 4/mmm
(4/m 2/m 2/m)
Unit cell111.00
Identification
ColorColorless
TwinningP4/nmm
CleavagePerfect on {001}
Mohs scale hardness2.5
|re|er}}Vitreous
StreakWhite
DiaphaneityTransparent
Specific gravity4.54
Density4.54
Optical propertiesUniaxial (-)
Refractive indexnω = 1.656(2)
nε = 1.652(2)
Birefringence0.004
Ultraviolet fluorescenceNone
SolubilitySoluble in water

Zhangpeishanite is a mineral named after Zhang Peishan (Chinese: 张培善), a Chinese mineralogist at the Institute of Geology of the Chinese Academy of Sciences, in recognition of his contributions to studying the mineralogy Bayan Obo deposit, where the mineral is mined. The Bayan Obo deposit is also known for being a world class deposit. The mineral got approved by the IMA in 2006 but was published two years after its approval.[2] The mineral consists of barium chloride fluoride.[3]

Properties

Some of the datas collected about zhangpeishanite were carried out on a synthetic equivalent of the mineral, such as cleavage and refractive index, due to zhangpeishanite's minute grain size.[2] The mineral is isostructural with matlockite.[4] It is a member of the matlockite group, and it is the barium dominant analogue of rorisite and matlockite. It is associated with barite, hematite, norsethite and fluorite.[5] The inclusions form as bands within fluorite. The mineral occurs in fluorite as inclusions, up to 100 μm. However, they are typically much smaller, about 50 μm.[2] It consists of barium mostly (71.21%), chlorine (18.94%) and fluorine (9.85%).[6] Singular crystals can be obtained at 1500 K by solid-state reaction between BaF2 and BaCl2.[7]

References