Graphite Lump ~~~ Pencil ~~~ Cut Diamond ~~~ Graphite Structure Graphite and Diamond Dust: Pencil Lead and Jewels Several mattresses are described as having foams or fibers infused with graphite or diamond particles. Graphite and diamond are two kinds of carbon crystals. Both are pure carbon, but they differ in the crystalline structure. The structural difference makes diamond extremely hard and graphite relatively soft. Real diamond particles (a.k.a. diamond dust) are very abrasive and...