Carpathite, A Rare Fluorescent Organic Mineral
Carpathite (formerly called karpatite) is a very interesting fluorescent mineral. The vast majority of minerals (fluorescent and non-fluorescent alike) are composed of inorganic, crystalline, compounds. Carpathite however, is a very rare, crystalline organic hydrocarbon mineral. It has the molecular formula C24H12 and is the naturally occurring mineral form of the polycyclic aromatic hydrocarbon compound coronene. The fluorescence of this mineral is due to excitation of the pi electrons associated with the multiple conjugated double bonds in the polycyclic aromatic ring structure. Carpathite is named after the Carpathian Mountains, where it was first described in 1955 for an occurrence in Transcarpathian Oblast, Ukraine.
This specimen of carpathite is from the Picacho Mine, Picacho Peak, Diablo Range, San Benito Co., California, and contains sprays of yellow carpathite crystals on a matrix of brown jasper, red cinnabar and light quartz. Under both short wave and long wave UV, the carpathite fluoresces bright blue/white. The size of this specimen is 55 x 53 x 33 mm, and it weighs 77 grams.
As shown above, under short wave UV (254 nm), the Carpathite fluoresces bright blue/white.
Under long wave UV (365 nm), the fluorescent response is nearly identical to that seen under short wave UV.
Under visible light this specimen is quite attractive, and features sprays of yellow carpathite crystals on a matrix of brown jasper, red cinnabar and light milky quartz.