Carpathite

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Carpathite
Carpathite-258272.jpg
Carpathite from New Idria District, California USA
General
CategoryOrganic mineral
Formula
(repeating unit)
C24H12
Strunz classification10.BA.30
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/c, P21/n
Unit cella = 10.03 Å, b = 4.69 Å,
c = 16.01 Å; β = 111°; Z = 2
Identification
ColorYellow, yellowish brown on exposure
Crystal habitAcicular to thin tabular in bladed groups and fibrous radiating aggregates
CleavagePerfect on [001], [100] and [201]
FractureSplintery
TenacityFlexible, nearly plastic
Mohs scale hardness1.5
LusterVitreous - adamantine
StreakYellow white
DiaphaneityTransparent
Specific gravity1.35
Optical propertiesBiaxial (+/-)
Refractive indexnα = 1.760 - 1.780 nβ = 1.780 - 1.982 nγ = 2.050 - 2.150
Birefringenceδ = 0.290 - 0.370
Other characteristicsFluorescent - electric blue to blue-green
References[1][2][3][4]

Carpathite (also pendletonite and karpatite) is a very rare hydrocarbon mineral. It is the mineral form of the polycyclic aromatic hydrocarbon coronene with formula: C24H12.

Discovery[edit]

It was first described in 1955 for an occurrence in Transcarpathian Oblast, Ukraine. It was named for the Carpathian Mountains. It has also been reported from the Presov Region of the Slovak Republic, the Kamchatka Oblast in Russia and from San Benito County, California.[2]

Occurrence[edit]

It occurs at the contact zone of a diorite intrusive into argillite within cavities in the Ukraine. In the California occurrence it appears as a low temperature hydrothermal phase. It is associated with idrialite, amorphous organic material, calcite, barite, quartz, cinnabar, and metacinnabar.[4]

References[edit]