What will happend if a diamond is heated at a temparature of 1200c?

what will happend after heated the diamond?|||Diamonds which had not been heated above about 1,200掳 C gave diamond diffraction patterns only, those which had been heated to 2,000掳 C gave graphite patterns only, and those which had been heated to about 1,600掳 C. gave both diamond and graphite patterns and also some extra spots not due to either diamond or graphite.|||we all know that diamond is a carbon compound. so if any carbon compound is heated beyond its melting point, it turns to pure carbon, just like the ashes left behind, after burning paper