Diamond grading agencies such as Gemological Institute of America (GIA), American Gem Society Laboratories (AGSL), and European Gemological Laboratory (EGL), exist with the sole purpose of certifying and verifying all the essential attributes that define an extraordinary diamond. The most respected and trusted of these agencies is the GIA.

Each diamond graded by these diamond laboratories is inspected by at least three to six gemologists. A certificate is issued after careful evaluation, verifying the diamond's cut, clarity, color, shape, and weight. The certificate is the diamond's blueprint. It can either be a diamond grading report or a diamond dossier.

Each Coby Madison diamond purchase is accompanied by a diamond certificate issued from one of these top diamond agencies. When choosing and considering diamonds for purchase, those that possess certificates or grading reports assist one in making a better and more informed decision.

G.I.A. Certified Diamonds

Because GIA is the number one diamond laboratory in the world, any diamond or gemstone submitted to them is considered as having accurate and consistent quality assessment. Each stone is carefully inspected by an average of four to five gemologists, who individually rate each stone according to its fundamental attributes. GIA's certificates or grading reports have become a seal of diamond integrity across the globe. GIA issues two types of reports namely, the official GIA document and the GIA dossier. Full-issued GIA documents include a full description of the diamond and a plotting of the stone's characteristics.

E.G.L. Certified Diamonds

Unlike the GIA, EGL certifies diamonds for a profit. Since EGL is not engaged in the trade of diamonds, it has earned a reputation for impartial and reliable diamond appraisals. EGL provides the fifth C for every diamond - the Certificate. Each diamond certificate from EGL includes identifying information about the stone to include cut, clarity, color, and carat weight. It also indicates quality of workmanship such as polish and proportions. A photo of the laser inscription on the diamond's girdle may also be found on the certificate, which can either be a full-size certificate, a mini certificate, or a credit card-sized certificate.