Graphite is found in pencil "lead" and ball-bearing lubricants.
Among the non-crystalline allotropes of carbon are coal, lampblack, charcoal, carbon black, and coke. Coke is nearly pure carbon formed when coal is heated in the absence of air.
No other element, except for hydrogen, occurs in even a fraction of that number of compounds.
French physicist René Antoine Ferchault Reaumur (1683-1757) believed carbon might be an element.
He studied the differences between wrought iron, cast iron, and steel.
It is not unusual for two atoms of an element to combine with each other. Carbon has the ability to make virtually endless strings of atoms. There is almost no limit to the size and shape of molecules that can be made with carbon atoms.
If one could look at a molecule of almost any plastic, for example, a long chain of carbon atoms attached to each other (and to other atoms as well) would be evident. (See accompanying diagrams.) Buckyballs are a recently discovered form of pure carbon.