Graphite. Macrophotograph of a specimen of graphite, a form of carbon that occurs naturally close to the Earth's surface. It is formed by stacked graphene sheets. Graphite is a soft, steel-gray to black, hexagonally crystallized allotrope of carbon with a metallic luster and a greasy feel, used in lead pencils, lubricants, paints, and coatings, that is fabricated into a variety of forms such as molds, bricks, electrodes, crucibles, and rocket nozzles. Also called black lead, plumbago.This specimen is from Sri Lanka and shows a detail of 13mm across.