Kratochvílite

Kratochvílite
General
Category Organic mineral
Formula
(repeating unit)		 C13H10
Strunz classification 10.BA.25
Crystal system Orthorhombic
Crystal class Pyramidal (mmm)
Space group Orthorhombic
H-M symbol: (mm2)
Space group: Pnam
Identification
Color White
Streak White
Optical properties Biaxial (+)
Refractive index nα = 1.578 nβ = 1.663 nγ = 1.919
Birefringence δ = 0.341
References [1][2][3]

Kratochvilite is a rare organic mineral formed by combustion of coal or pyritic black shale deposits. It is a hydrocarbon with the formula of either C13H10 or (C6H4)2CH2. It is a polymorph of the aromatic hydrocarbon fluorene. It forms white, yellow to brown crystals in the orthorhombic system which occur often as a druzey encrustation. It has a specific gravity of 1.21 and a Mohs hardness of 1 to 2.

It was first described from the Nejedly mine in Bohemia, Czech Republic in 1937.[2]

References

  1. ↑ Kratochvilite data on Webmineral
  2. 1 2 Mindat.org
  3. ↑ The Handbook of Mineralogy



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