A MYSTERY form of carbon has finally been identified as a diamond-graphite hybrid.
Carbon is well-known for morphing into many different forms such as graphite and diamond. Graphite is made of parallel sheets of carbon atoms held together by weak chemical bonds. In diamond, the bonds between the carbon atoms are much shorter and stronger.
For years, scientists have been puzzled by a form that appears when graphite is squeezed under the pressure of 170,000 atmospheres. The soft, grey carbon becomes transparent and as hard as diamond. But release the pressure and it turns back into ordinary pencil “lead”.…
