Carpathite

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Carpathite
Carpathite-258272.jpg
Carpathite from New Idria District, California USA
General
Category Organic mineral
Formula
(repeating unit)
C24H12
Strunz classification 10.BA.30
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/c, P21/n
Unit cell a = 10.03 Å, b = 4.69 Å,
c = 16.01 Å; β = 111°; Z = 2
Identification
Color Yellow, yellowish brown on exposure
Crystal habit Acicular to thin tabular in bladed groups and fibrous radiating aggregates
Cleavage Perfect on [001], [100] and [201]
Fracture Splintery
Tenacity Flexible, nearly plastic
Mohs scale hardness 1.5
Luster Vitreous - adamantine
Streak Yellow white
Diaphaneity Transparent
Specific gravity 1.35
Optical properties Biaxial (+/-)
Refractive index nα = 1.760 - 1.780 nβ = 1.780 - 1.982 nγ = 2.050 - 2.150
Birefringence δ = 0.290 - 0.370
Other characteristics Fluorescent - 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]

  1. ^ Mineralienatlas
  2. ^ a b Mindat with location data
  3. ^ Webmineral data
  4. ^ a b Handbook of Mineralogy