Coal ball

period: Carboniferous (358.9-298.9 million years ago)

excavation site: Morcinek mine pit, Kaczyce (Cieszyn Silesia)

Carbon is a flammable sedimentary rock created as a result of carbonisation of vegetable matter, such as calamites or polystichum. Among the sediments of upper carbon, in black coal mine pit Morcinek, on the depth of 1400 m rare coal ball was found. The creation of such coal is connected with thermic activity of igneous objects from the centre of the Earth against the existing layers of carboniferous sediments.

The piece comes from the collection of Geological Museum of the National Geological Institute – National Research Institute.