Patent ID: 6835365
Filing Date: 2004-12-28
Classification: B01J

Abstract:
A method of producing a mass of diamond crystals, wherein the diamond crystals of the mass are predominantly macroscopically faceted single crystals, comprising the steps of:providing a source of diamond crystals which are substantially free of macroscopically faceted surfaces, contacting the source of diamond crystals with a suitable solvent/catalyst, thereby producing a reaction mass, subjecting the reaction mass to conditions of elevated temperature and pressure suitable for crystal growth in the reaction zone of a high temperature/high pressure apparatus, removing the reaction mass from the reaction zone, and recovering the diamond crystals from the reaction mass, wherein the conditions of diamond crystal growth are such that a supersaturation driving force necessary for diamond crystal growth is generated predominantly by the difference in surface free energy between surfaces of the diamond crystals having a low miller index surface and surfaces of the diamond crystals having a high miller index surface, thereby converting the source diamond crystals to diamond crystals having macroscopic facets of low miller index.