Charcoal
noun
すみ
炭 (すみ) Charcoal
墨 (すみ) Ink, Black Ink
隅 (すみ) Corner, Nook, Recess
石炭 (せきたん) Coal
炭素 (たんそ) Carbon
Charcoal comes from burned wood. Coal comes from rocks in a mine. They both contain the element Carbon.