Category Organic mineral Strunz classification 10.BA.25 Crystal class Pyramidal (mmm) | Formula
(repeating unit) C13H10 Crystal system Orthorhombic | |
Space group Orthorhombic
H-M symbol: (mm2)
Space group: Pnam | ||
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.
References
Kratochvílite Wikipedia(Text) CC BY-SA