An article of jewelry for wearing on the body may comprise a sintered polycrystalline diamond compact with substantially no metal catalyst. As many of the metal catalysts commonly used in the art are known to cause skin irritation, such a sintered compact with substantially no metal catalyst may be more biocompatible than previously known. A method for forming such a biocompatible sintered polycrystalline diamond compact comprises mixing diamond powder and metal catalyst powder into a mixture and sintering the mixture under elevated temperature and pressure conditions to form a sintered compact. The sintered compact may then be leached in an acid or other solution to substantially remove the metal catalyst from the sintered compact.