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.
Virginia earned the nickname, Mother of Presidents for good reason. 1  Though her contribution wained after 1850, The Old Dominion gave birth to eight men who attained the office of President of the United States: 1  George Washington: 1st President of the United States, George Washington was born on February 22, 1732, on Pope Creek in Westmoreland County. The nation's military leader during the Revolutionary War, George Washington was a unanimous choice. He served for two terms, from 1789 to 1797. [ More] Thomas Jefferson: 3rd President of the United States, Thomas Jefferson was born on April 13, 1743 at Shadwell plantation, Gooch County. Following John Adams of Massachusetts, Thomas Jefferson served two terms from 1801 to 1809. [ More] James Madison: 4th President of the United States, James Madison was born on March 16, 1751 in Port Conway. He served two terms from 1809 to 1817. [ More]