Shungite

Shungit (also: Schungit, Schungite coal, Inostranzeff'sches Schungit, algae and carbon derived from English shungite ) is a naturally occurring Precambrian only a few places, black stone age, which consists mainly of carbon.

Description

Schungite can contain up to 98 % carbon and having a density of 1.9 to 2.1 g / cm ³. The rock name goes back to Alexander Alexandrovich Inostranzew, the Schungit first described in 1880.

Shungites have probably made before at least 600 million years ago from digested sludge. As starting material, presumably seaweed served. They contain the very rare naturally occurring fullerenes C60 and C70.

In the geological research Shungites be divided into three categories of quality, which differ in chemical composition.

• Category I: Precious Schungit ( glassy, ​​black and metallic luster; carbon content to 98 %)
• Category II: Black Schungit ( carbon content of about 50 to 70%)
• Category III: Gray Schungit ( carbon content of about 30 to 50 %)

Schungitgestein which has an even lower proportion of carbon is referred to as shungite carbon.

Occurrence

Known localities are Eastern Finland and Russia ( Karelia, the Lake Onega in the Shungaregion who gave the stone its name, and the Lake Ladoga ), often in areas where even oil shale is found. Other localities are located in India in the areas of Tamil Nadu, Chennai (Madras ), Cuddapah ( Kadapa ), Kodur Mandal and Mangampeta.

Use

Shungite is suitable as a black pigment for the production of colors, and is designated as shungite black. Furthermore, Shungitkohle be used as a substitute for activated carbon filters. Also jewelry pendants, necklaces and ornaments are II (black Schungit ) made ​​Schungite the category that can be sanded and polished to a high gloss.