Carbon naturally occurs in three forms: graphite, diamond and fullerenes. The most stable, and therefore most common, allotrope of carbon is graphite. Diamonds are less common, as the crystals form at a layer of the Earth's crust that is not commonly in contact with the surface.
Fullerenes are the third allotrope of carbon, and in many ways they are the most remarkable. Fullerenes were first discovered in 1985. The teams responsible for their discovery named the molecules after the legendary architect Buckminster Fuller, since their discrete crystal lattices curl around on themselves to make shapes strongly reminiscent of Fuller's famous geodesic domes.