Carpathite

Karpathit (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 C24H12 and forms yellow to yellow- green, transparent crystals, which have a similar gloss glass or diamond. Chemically, it is the polycyclic aromatic hydrocarbon coronene.

Special Features

Under irradiation with long-wave UV light Karpathit is excited to a strong, straw-yellow fluorescence. The Mohs hardness is like that of talc only 1, which means that the mineral can be scratched with a fingernail already. With a density of 1.35 to 1.4 g / cm ³, it is only slightly heavier than water (1 g / cm ³).

Etymology and history

Karpathit 1955 was first found and described, and after his first locality (type locality) Transcarpathia (Ukraine ) named.

Classification

In the classification by Strunz Karpathit is counted among the organic compounds. In the outdated eighth edition it forms with dinit, fichtelite, Flagstaffit, Kratochvílit, Hartit, Hoelit, Idrialin, Ravatit, Refikit and Simonellit a subset of the nitrogen-free hydrocarbons. In the new Ninth Edition, it forms a separate subgroup of the subdivision 10.BA of the hydrocarbons.

In the classification by Dana Karpathit forms a separate subgroup of the " salts of organic acids and hydrocarbons ."

Education and Locations

Karpathit formed by hydrothermal processes low temperature in cavities of diorite porphyry rocks. He is accompanied by barite, calcite, cinnabar, Idrialin, quartz and others.

As localities have so far besides its type locality Transcarpathian only in Prešov in Slovakia and California in the United States.

Crystal structure

Crystallizes in the monoclinic Karpathit prismatic crystal system in the space group P 21 / c and P 2 / c with lattice parameters a = 10.035 Å; b = 4.695 Å and c = 16.014 Å; β = 69 ° and two formula units per unit cell.