Diamond certificates, or grading reports, as they are known in the diamond industry, are often called the fifth C, in addition to the well-known 4Cs of diamond stones: carat weight, cut, color, and clarity.
A diamond certificate is a report created by a team of gemologists. The diamond is evaluated, measured, and scrutinized using trained eyes, a jeweler’s loupe, a microscope,and other industry tools. A completed certificate includes an analysis of the diamond’s dimensions, clarity, color,  cut grade, polish, symmetry, and other characteristics.