Coal is formed by millions of years of intense pressure on decaying biological material. It is suspected that it comes primarily from swamp plants, like peat (one reason that coal was relatively common in Britain). It is also believed that all coal was formed during the (conniferous?) era.
Folklore of Coal Stones
Coal is thought ultimately to derive its name from the Old English col but this actually meant charcoal at the time; coal was not dug for prior to the later Middle Ages i.e. after c. 1000 AD. Mineral coal was referred to as sea-coal since it was found washed up on beaches occasionally.
It is associated with the astrological sign Capricorn. It is carried by thieves to protect them from detection and to help them to escape when pursued. To dream of {burning, or burnt?} coals is a symbol of disappointment, trouble, affliction and loss, unless they are burning brightly, when the symbol gives promise of uplifting and advancement.
/History of coal mining.
/Major? coal producing regions.
/Major? coal exporters.
/Graph? of worldwide coal extraction over the last N hundred years.
/Coal? mining techniques.
Also a colour.