Oncolite Cabochon Cab Russian Stone Gemstone Mineral


1 in stock



This is the oval oncolite cabochon. Dimensions: 1.6 x 1.1 x 0.2″ (4 x 2.9 x 0.5cm). Weight – 0.4oz (12 grams). Origin: Russia, Siberia.

Some information about oncolite:

Oncolites – sedimentary structures composed of oncoids, which layered structures formed by cyanobacterial growth.

Oncolites are very similar to stromatolites, but, instead of forming columns, they form approximately spherical structures. The oncoids often form around a central nucleus, such as a shell fragment, and a calcium carbonate structure deposited by encrusting microbes.

Oncolites are indicators of warm waters in the photic zone, but are also known in contemporary freshwater environments. These structures rarely exceed 10 cm in diameter.

Additional information

Weight 12 g