English: Shungite from the Precambrian of Russia.

Shungite is a rare type of asphaltite from Russia. It is composed of noncrystalline, non-graphitized carbon. It occurs in the upper Zaonezhskaya Formation, a Precambrian-aged platform succession of sedimentary rocks. In the unit, this unusual material occurs as stratiform shungite, diapiric shungite, redeposited clastic/detrital shungite, and vein shungite. The specific origin is uncertain - the literature refers to shungite as either pyrobitumen or Precambrian coal or carbonized hydrocarbons or highly-evolved bitumen.

Shungite is black-colored, slightly lightweight for its size and varies from dull lustered to glassy-lustered. The latter variety looks somewhat like obsidian and is called "elite shungite" or "noble shungite" by rockhounds - it is rare and ~98% carbon (see photos elsewhere in this album). The specimen seen here is ordinary shungite - a brecciated texture is present.

Host unit: Zaonezhskaya Formation, Ludikovi Group, middle Paleoproterozoic, 1.98 to 2.09 Ga; greenschist-facies metamorphism at 1.8 Ga

Locality: unrecorded locaity in the shungite mining field, northern Lake Onega area, southern Karelia Republic, south of the White Sea, southeastern Fennoscandian Shield, northwestern Russia