CBSE Class 10 Answered

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.