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 -- As we close in on Election Day in a race that may well be decided right here in Ohio, are you aware that no fewer than eight of America's presidents have been Ohioans themselves? The only other state that can claim that many presidents is Virginia, and Virginia and Ohio like to bicker back and forth over which one owns the nickname, The Mother of Presidents. Well, here on The Plain Dealer's 90-Second Know-It-All desk, we like to say that a little knowledge goes a long way.