Bituminous coal is a rock more than half of which consists of organic compounds, that is the decayed ancient plant matter. The development of vascular plants on Earth was the reason for this coal formation. Their decayed matter accumulated in marshes in the Devonian period (from 350 to 420 million years ago). At first, it turned into peat in an anaerobic environment. Then, pressured by the surrounding strata and heat, it changed into lignite (brown coal). In turn, it transformed into anthracite (hard coal) that is a dense stone of intense black or grayish-black color. The more the coal got compacted, the better its flaming qualities became.

The largest deposits of bituminous coal were formed on the planet 290 — 350 million years ago. This period in geological history is called the Carboniferous.

People had known natural fuel since ancient times. They learned how to mine for coal in China and ancient Greece. Aristotle and his student Theophrastus of Eresos mentioned coal or anthracite in their writings. And in Russia, it began to be mined in the 15th century.

In modern industry, coal is subjected to semi-coking. It gets heated to a temperature of 500 — 550 degrees Celsius without air. As a result, volatile products and a solid inflammable residual, used as a fuel, are formed. Then they get coal tar, light oils, and gas out of them. These components are essential to produce medicines, paints, solvents, preservatives, fertilizers, and insect control agents.

Bituminous coal can be found all over the world. There are about 3000 deposits and basins. They are mined in an open or closed way. In the first case, open-pits are formed, and in the second case, the rock is extracted from mines or tunnels. The mining method is chosen depending on how the coal seam is located underground. If it lies at depths of up to 100 meters, they choose the open-pit mining.