Graphite is composed entirely of carbon atoms, as is diamond. Their dramatically different physical properties are attributed to their different lattice structures. Graphite is the low-temperature/pressure polymorph of carbon, while diamond is the high T/P polymorph.
Pronunciation: GRAPH•ite (accent on capitalized syllable)
Color: lead gray
Streak: lead gray
Luster: metallic
Diaphaneity: opaque
Hardness: 1-2
Specific gravity: 2.23
Cleavage/fracture: 1
Other distinguishing properties: Graphite leaves a gray residue on your hands due to its softness -- graphite is easily scratched with a fingernail. Usually mixed with kaolinite, it has been used in pencils as "pencil lead."
Klein, C., and Hurlbut, C.S., Jr., 1999, Manual of Mineralogy (after James D. Dana) [21st edition, revised]: New York, John Wiley & Sons, 682 p.
Los Angeles County Museum of Natural History, The Photo Atlas of Minerals: nhm.org/pam/
Return to the Minerals page.
