The Cercs Mines Museum.
Block of charcoal, lignite, from the Sant Romà mine. Bituminous coal is a mineral fuel that was formed 250 million years ago, when large areas full of vegetation were buried in swamps.
In the process undergone to turn into coal, some trees were not completely decomposed and were transformed into charcoal, large compact chunks of coal. Sometimes in the coal fossils you can find fossils of animals and plants which were typical of the era in which they were formed.
