††††Coal is a hard, black mineral found naturally in layers beneath the earth. It is mostly made of carbon from the fossilized remains of plants.
Coal was used around 1000 AD in China as the explorer Marco Polo discovered on his travels. From this time onwards, people started burning coal instead of wood and started mining for it, a practice which became a huge industry in Britain in the 17th century.
Coal is still used as a fuel, although less often than in previous decades because it causes serious atmospheric pollution. Coal is also used in the chemical industry.
