Shungite

Hardness: 3-4 (Mohs Scale); Color: Jet black to dark gray, sometimes with a metallic sheen; Luster: Sub-metallic to dull; Crystal structure: Amorphous (no distinct crystal structure); Cleavage: None (conchoidal fracture); Specific gravity: 1.8-2.1 (can vary with carbon content)

Shungite is a Precambrian carbonaceous rock that formed approximately 2 billion years ago. It is believed to have originated from the organic matter of ancient sapropel deposits (accumulations of micro-organisms and algae) that were subsequently subjected to high temperatures and pressures, transforming them into a unique form of carbon. The high carbon content (up to 98% in some varieties) and the presence of fullerenes are distinctive features.

Historically, shungite has been used for water purification and as a natural pigment. In modern times, it is marketed for various applications including water filtration, EMF protection (though scientific evidence is limited), in ceramics, as a filler in rubber and plastics, and in fertilizers. Due to its unique appearance and purported beneficial properties, it is also used in jewelry and decorative objects.

Shungite is notable for containing fullerenes, which are spherical carbon molecules (like buckyballs). The discovery of fullerenes earned a Nobel Prize in Chemistry in 1996. While fullerenes are found in shungite, their concentration and biological activity are subjects of ongoing scientific research. The exact origin and unique properties of shungite continue to fascinate scientists.

In the field, shungite is identified by its distinctive black color, often with a dull to sub-metallic luster, and its amorphous, sometimes slightly porous, texture. It is non-magnetic. A common identifying characteristic is that higher quality shungite (with higher carbon content) can conduct electricity, which can be tested with a multimeter. It leaves a black mark on skin or paper when rubbed. The primary source of shungite is the Karelia region of Russia, particularly near Lake Onega, where the largest and oldest deposits are found. Due to its unique carbon structure, it often feels lighter than other rocks of similar size.