Joory Diamonds Certified diamonds are diamonds that have been graded by a gem laboratory based on their “4 C’s” attributes of Carat Weight, Color, Clarity & Cut. When shopping for a diamond, it is highly recommended to purchase a certified diamond to ensure the quality of the stone. Here at “Joory Diamonds”, we managed not just to certify the stone but the whole piece of Jewelry by having a partnership with HRD Antwerp which is leading authority in diamond certification.