Rosickýite

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Rosickyite
General
Category Native element mineral
Formula
(repeating unit)
S
Strunz classification 1.CC.05
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: P 2/c
Unit cell a = 8.455(3) Å, b = 13.052(2) Å, c = 9.267(3) Å; β = 124.89(3)°; Z=4
Identification
Color Colorless to pale yellow, green tinge
Crystal habit Equidimensional to thin tabular crystals, efflorescences
Crystal system Monoclinic
Twinning On {101}, with twin lamellae parallel to [010]
Cleavage None
Mohs scale hardness 2 - 3
Luster Adamantine
Diaphaneity Transparent to translucent
Specific gravity 2.07
Optical properties Biaxial (-)
References [1][2][3]

Rosickyite is a rare native element mineral that is a polymorph of sulfur. It crystallizes in the monoclinic crystal system and is a high temperature, high density polymorph. It occurs as soft, colorless to pale yellow crystals and efflorescences.[1][2]

It was first described in 1930 for an occurrence in Havirna, near Letovice, Moravia, Czech Republic. It was named for Vojtĕch Rosický (1880–1942), of Masaryk University, Brno.[1][2]

Rosickyite occurs as in Death Valley within an evaporite layer produced by a microbial community. The otherwise unstable polymorph was produced and stabilized within a cyanobacteria dominated layer.[4]

References[edit]

  1. ^ a b c Handbook of Mineralogy
  2. ^ a b c Rosickyite on Mindat.org
  3. ^ Rosickyite on Webmineral.com
  4. ^ Susanne Douglas and Heixong Yang, Mineral biosignatures in evaporites: Presence of rosickyite in an endoevaporitic microbial community from Death Valley, California, Geology, Dec. 2002, v 30, pp1075-1078