All stones are graded using the same standards. With certified diamonds you can be sure that the diamond you're purchasing is exactly what is on the certificate. Comparing stones of the same carat weight or same color grade becomes easier. Appraisals for certified diamonds are simple. Submit your stone's characteristics from the certification and an appraisal can be given without the stone ever leaving your possession.
Security is another advantage to having a certified stone.
Since every diamond is unique, positive identification of the stone is possible. The certificate contains all of the information about the diamond. The stone is graded for clarity and color while the carat weight of the diamond and its measurements are also recorded on your certificate. Carat -The weight of the diamond is in carats. Most diamonds have inclusions or surface blemishes that cannot be seen with the naked eye.