Graphite - C

Habit: Typically black or silvery-grey, most common habit is massive, columnar, granular or earthy masses. Crystals with well-defined, hexagonal habit and spheroidal aggregates are rare. Dull earthy or Metallic Luster; opaque, transparent only in extremely thin flakes

Environment: Formed by metamorphism of sedimentary carbonaceous material, such as limestones rich in organic material. Also found as the primary mineral in some igneous rocks.

Etymology: From the Greek graphein, "to write", an allusion to its ancient use as a drawing pencil.