RUSS LAPPA / SCIENCE PHOTO LIBRARY RUSS LAPPA / SCIENCE PHOTO LIBRARY
Graphite, a soft, slippery, crystalline form of carbon. Graphite occurs in a variety of rocks including marbles, shists and granites and is made artificially by burning coke in the absence of oxygen. It is a good conductor of heat and electricity and has a variety of uses including electrical contacts, high-temperature equipment and as a solid lubricant. Pencil "lead" is made of graphite mixed with clay. Natural graphite is sometimes referred to as plumbago, black lead or Flanders stone. Carbon forms many compounds and is the basis of all organic chemistry. The radio- active isotope Carbon-14 is used in carbon dating.
Model release not required. Property release not required.