Here’s the Inside Scoop on Diamond Grading Reports
Unlike pedigree papers, however, the certificate does not increase the value of the stone, but rather provides a scientific report of each diamond’s authenticity and quality. Most Diamond Grading Reports are prepared either by the American Gem Society (AGS) or the Gemological Institute of America (GIA), which established the International Diamond Grading System in 1953. Reputable diamond grading reports are unbiased; neither the AGS nor the GIA is in the business of buying, selling or appraising diamonds.
Grading reports include the following highly standardized criteria, which are recognized worldwide:
• Shape, cut and cut grade: Cut grade is determined by the stone’s face-up appearance. • Measurement: Dimensions are given in millimeters. • Weight: Given to the nearest point, or 1/100th of a carat. • Color Grade: Rated on an alphabetical scale, D-F diamonds are nearly colorless, while S-Z are actually light yellow. Fancy-colored diamonds are rated on a different scale. • Clarity Rating: Indicates the number of flaws, or inclusions, while a clarity plot denotes their size, location and type. • Finish: Evaluates facet placement and surface. • Polish: Rates the overall smoothness. • Proportion: Mapped to show relationships between depth, table (top facet), girdle and culet (bottom facet). • Symmetry: Describes the evenness of the diamond’s outline, as well as facet alignment, shape and placement. • Fluorescence: Indicates the strength of the diamond’s color when viewed under ultraviolet light (no color or blue color is best). • Additional comments: Anything else of note.
Though diamond grading reports never assign a monetary value, the detailed quality analyses allow buyers to make educated decisions about the diamonds they are evaluating for purchase, particularly if the diamonds are of similar weight or quality. If any of the information in the report is unclear, we’d be happy to review it with you and answer any questions you may have.
