But unlike their agricultural brethren, they do not result in food shortages and those wood chips could be mixed in with coal before it is combusted.

FORBES: Biomass Breathing New Life Into Coal Plants

When he shone a light up through it, he could see fine-grained particles of silica, known as chert, mixed in with what looked like coal.

NEWYORKER: The Martian Chroniclers

Rick Santorum tried to capitalize in New Hampshire by emphasizing the blue-collar sensibilities he inherited as the grandson of coal miners, though with mixed success.

WSJ: A Changed GOP Explains Election Twists