Laurionite

Laurionite (PbCl(OH)) is a lead halide mineral. It forms colorless to white crystals in the orthorhombic crystal system and is dimorphous with paralaurionite, both members of the matlockite group.[2]

Laurionite
Laurionite crystals in a vug from the Laurium district of Greece
General
CategoryHalide minerals
Formula
(repeating unit)
PbCl(OH)
IMA symbolLri[1]
Strunz classification3.DC.05
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPnma
Unit cella = 7.111, b = 9.6987
c = 4.0203 [Å]; Z = 4
Identification
ColorColorless, white
Crystal habitElongated tabular prismatic crystals
CleavageDistinct on {101}
TenacityFlexible
Mohs scale hardness3 - 3.5
LusterAdamantine, pearly
StreakWhite
DiaphaneityTransparent
Specific gravity6.241
Optical propertiesBiaxial (-)
Refractive indexnα = 2.077 nβ = 2.116 nγ = 2.158
Birefringenceδ = 0.081
2V angleMeasured: 70°
SolubilitySleight in cold water
References[2][3][4][5]

It was first described in 1887 for an occurrence in the Laurium District, Attica, Greece, and named after the town Laurium.[2] It occurs as an oxidation product in lead ore deposits, and is also produced on lead-bearing slag by reaction with saline solutions. It occurs associated with paralaurionite, penfieldite, fiedlerite, phosgenite, cerussite and anglesite.[3]

References


This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.