Carpathite

Carpathite
General and classification
chemical formula	C 24 H 12
Mineral class; (and possibly department)	Organic compounds - hydrocarbons
System no. to Strunz ; and to Dana	10.BA.30 ( 8th edition : IX / B.02) ; 03/50/07/01
Crystallographic Data
Crystal system	monoclinic
Crystal class ; symbol	monoclinic prismatic 2 / m
Space group	P 2 1 / c or P 2 / c
Lattice parameters	a = 10.035 Å ; b = 4.695 Å; c = 16.014 Å ; β = 69 °
Formula units	Z = 2
Physical Properties
Mohs hardness	1
Density (g / cm 3 )	1.35 to 1.4
Cleavage	completely after [001]
Break ; Tenacity	brittle
colour	yellow to yellow-green
Line color	light yellow
transparency	transparent
shine	Diamond luster, glass luster
Crystal optics
Refractive indices	n α = 1.760 to 1.780 ; n β = 1.780 to 1.982 ; n γ = 2.050 to 2.150
Birefringence	δ = 0.290 to 0.370
Optical character	alternating biaxially
Pleochroism	unavailable
Other properties
Special features	fluorescent

Carpathite (formerly Pendletonit , renamed in 1971) is a rarely occurring hydrocarbon - mineral from the mineral class of organic compounds . It crystallizes in the monoclinic crystal system with the chemical composition C ₂₄ H ₁₂ and forms yellow to yellow-green, transparent crystals with a luster similar to glass or diamond. Chemically, it is the polycyclic aromatic hydrocarbon coronene .

Etymology and history

Karpathite was found and described for the first time in 1955 and named after its first location ( type locality ) Transcarpathia (Ukraine).

classification

In the Strunz system, carpathite is one of the organic compounds. In the outdated eighth edition , it forms a subgroup of nitrogen-free hydrocarbons with Dinit , Fichtelit , Flagstaffit , Kratochvílit , Hartit , Hoelit , Idrialin , Ravatit , Refikit and Simonellite . In the new ninth edition , it forms a separate subgroup of subdivision 10.BA of hydrocarbons.

In the Dana system , carpathite forms its own subgroup of the "salts of organic acids and hydrocarbons".

Crystal structure

Carpathite crystallizes in the monoclinic prismatic crystal system in the space group P 2 ₁ / c or P 2 / c with the lattice parameters a = 10.035 Å ; b = 4.695 Å and c = 16.014 Å; β = 69 ° and two formula units per unit cell .

properties

Structure of corons

When exposed to long-wave UV light , carpathite is stimulated to produce a strong, straw-yellow fluorescence . The Mohs hardness is like that of talc only one, which means that the mineral can be scratched with a fingernail already. With a density of 1.35 to 1.4 g / cm³ it is only slightly heavier than water (1 g / cm³).

Education and Locations

Carpathite (yellow) as partial inclusion in microcrystalline quartz from the "Picacho Mine" near New Idria, San Benito County, California, USA

Carpathite formed by hydrothermal processes low temperature in cavities of diorite - porphyry - rocks . He is accompanied by barite , calcite , cinnabarite , idrialin , quartz and others.

So far, in addition to its type locality Transcarpathia, only Prešov in Slovakia and California in the USA have been found .

Web links

Commons : Carpathite - collection of images, videos and audio files

Mineral Atlas: Carpathite (Wiki)
Mineral data sheet - Karpatite (PDF 65 kB)

Individual evidence

↑ ^a ^b ^c ^d Webmineral - Karpatite (Engl.)
↑ ^a ^b ^c Karpatite at mindat.org (engl.)
↑ Entry on pendletonite. In: Römpp Online . Georg Thieme Verlag, accessed on June 7, 2014.
^ Dana Salts of Organic Acids Classification at webmineral.com. .

[Webmineral-1] Webmineral - Karpatite (Engl.)

[MinDat-2] Karpatite at mindat.org (engl.)

[3] Entry on pendletonite. In: Römpp Online . Georg Thieme Verlag, accessed on June 7, 2014.

[4] Dana Salts of Organic Acids Classification at webmineral.com. .