Coal

Types of coal 

The dicovery of coal is quite interesting. The first documented use of coal in the US was in 1748. Coal was used to produce "coal gas" to light up the gas lights in the cities. John Peter Sally descovered coal near Boone County.Coal was formed from the remains of swamp plants 300 to 400 years ago.
Types of coal:
Peat (coal precurser) slowly decay plant matter found in bogs, moors, and muskegs.










Lignite (Brown coal) Found in Alaska and western states, and used for electric power.

Bituminous coal ( black coal) a relatively soft coal containing a tarlike substance called bitumen.

Anthracite (Hard coal) Anthracite is the most metamorphosed type of coal. Coke ( coal product) is a fuel with few impurities and a high carbon.

http://www.fossil.energy.gov/education/energylessons/coal/gen_coal.html