Graphite is rather common, but fine crystals are rare. Most Graphite mining areas produce enormous quantities from a single or several large Graphite veins. Graphite has the same chemical composition as the mineral Diamond, but the atomic structure of Graphite and Diamond is entirely different. This causes almost opposite characteristics in their physical properties.
Much care should be given to Graphite specimens, especially thin crystals, which are fragile. It is very hard to wash crystals as they peel off and get ruined. Graphite will also smudge on its surface, and can get worn out if it is moved around too much. Graphite also smudges the hand if handled, and will smudge a paper or cardboard box if it is stored in one.
The "lead" in pencils is in fact composed of a mixture of Graphite and clay. There is no lead in pencils at all. Much of the commercially mined Graphite is used for pencil fillings. Its main function, however, is as a lubricant. It has many electrical uses, primarily because it is the only common nonmetal that is a good conductor of electricity.