Most people, when they refer to graphite, think of lead pencils. Indeed, the first documented use of graphite as a commercial writing material is traced to the area around Keswick in the Lake District where a high quality deposit of "writing graphite" was discovered in the middle of the 1500's. In fact, the word graphite is derived from the Greek word graphein which means "to write". To simplify matters, it may be easier to refer to graphite as being either natural or synthetic.
Natural graphite is a mineral found in disseminated crystalline flake and vein forms which is mined from open pit and underground mine operations. The principal sources of flake graphite are China, Brazil and Canada with Madagascar and Sri Lanka being primarily responsible for vein graphite. Flake graphite is typically found as discrete flakes and is characterised by a high degree of crystallinity with carbon purities varying between 80 and 95%. Vein graphite can be recognised by its light metallic sheen and needle-like particles. It is the most pure and has the highest level of crystallinity of the natural graphites and is also the rarest. In addition, there is a low grade of graphite known as amorphous which is akin to anthacite coal and is high in ash content.
Synthetic graphite is a by-product from the manufacture of graphite electrodes which are produced by the ultra high temperature treatment of calcined petroleum coke and coal tar pitch. This process produces an artifical form of graphite typically with 99% carbon content. The resulting machings from the graphite electodes are then milled to produce a high purity synthetic graphite powder having a dark grey to black appearance which offers excellent heat and electrical conductivity.
Our recommendation is that for all general lubrication purposes you should use natural graphite powder. If a superfine natural graphite product is required, then you should choose micronised graphite powder and if you are manufacturing, say using epoxy resin, then you should select synthetic graphite powder. We are always happy to send samples for you to experiment with and work out which product is best for you.