In what form is graphite found in nature?

This mineral is often found as foliated masses or small loose sheets, sometimes as black six-sided crystals with triangular markings on the basal plane. It is very soft (1-2 on the Mohs scale), feels greasy, very light, and shows perfect cleavage. Optically, it is opaque with a sub-metallic luster. Insoluble (in acids) and infusible (high melting point). Shows good electrical conductance. There is also an orthorhombic polytype which is less common.