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Carbon is known to most people as the lumps of black stuff that burn in fires. But if you think that this is its only form, you would be wrong! Carbon can be as white as elephants can be pink.

Carbon is a very flexible element - there are over sixteen million compounds of carbon, more than any other element. Because it has just the right size for fitting into the space between other molecules, it is capable of allotropes - commonly, diamonds and graphite, but more recently, a new allotrope, called white carbon or ceraphite, has been found.

White carbon was first made in 1969. It is unlikely to have existed naturally, as it has only been manufactured under extreme test conditions in a lab. It was produced at a high temperature (2550K, or 2277C) and low pressure, on the edges of graphite, another allotrope of carbon. Because of the change in conditions, the graphite sublimates and the white carbon forms as small crystals around it. These crystals can then be removed and examined. White carbon is transparent - it can be seen through - and birefringent - it has more than one index of refraction, which means it can split one ray of light into two separate rays.

Because so little is known about it, and it is very seldom-occurring, there are currently not many practical uses for white carbon. It has been reported to be extremely soft for a carbon product. In the future, however, more applications may be found: graphite is already a cheaper alternative to boron fibers, and white carbon, if it gets developed, may be a replacement for this. Confusingly, boron nitrite, which is used in sports equipment, is sometimes called 'white graphite'.