Safeopedia explains Coal Washing. Coal is a type of sedimentary rock that is formed by buried vegetation that is transformed by pressure and heat over long periods of time. Coal will eventually turn into diamond formations with enough time, pressure and heat. Impurities include slate and other non-organic rocks etc..
The number of presidents born per state are: 1  One: Arkansas, California, Connecticut, Georgia, Hawaii, Illinois, Iowa, Kentucky, Missouri, Nebraska, New Hampshire, New Jersey, Pennsylvania, and South Carolina. 2  Two: North Carolina, Texas, and Vermont.  Four: Massachusetts, and New York.
CLEVELAND, Ohio -- Seven of America's 44 presidents were born in Ohio, earning it the nickname, The Cradle of Presidents.. An eighth resided in and launched his campaign from Ohio. Meet the eight Ohioans who became U.S. president: William Henry Harrison (ninth), North Bend, Ohio, 1841. Whig. The Virginia-born Ohio resident was 68 years and 23 days old when he took the oath. He was the oldest president elected until Ronald Reagan took office in 1980. His term was cut short by pneumonia after a mere 32 days -- the shortest reign in U.S. history.