Evenkite

Evenkite
Evenkite from Dubnik, Slovakia
General
CategoryOrganic mineral
FormulaC24H50
IMA symbolEvk
Strunz classification10.BA.50
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPbcm
Unit cella = 7.47, b = 4.98, c = 65.85 [Å]; Z = 4
Identification
ColorColorless or pale yellow
Crystal habitTabular pseudohexagonal crystals, granular, disseminated
TwinningPolysynthetic
Cleavage{001} Perfect
Mohs scale hardness1
LusterWaxy
DiaphaneityTransparent
Specific gravity0.87
Optical propertiesBiaxial (+)
Refractive indexnα = 1.504 nβ = 1.504 nγ = 1.553
Birefringenceδ = 0.049
References

Evenkite is a rare hydrocarbon mineral with formula C24H50; specifically, H3C–(CH2)22–CH3, the alkane n-tetracosane. It occurs as very soft (Mohs hardness 1) transparent crystals, colorless to yellow, with a waxy luster. The softness is a characteristic of crystalline long-chain alkanes, which are the main constituents of paraffin wax.

Evenkite one of very few minerals that consist of crystalline hydrocarbons, which include carpathite (pure crystalline coronene, a polyaromatic hydrocarbon). It is also one of the few non-porous minerals that floats on water. It has been claimed to be the same as hatchettite.