Understanding a GIA Diamond Grading Report A Diamond Grading Report documents the specific characteristics of a diamond. The Gemological Institute of America (GIA) issues these reports, which is among the most respected organizations in the diamond industry. Features of the Diamond Grading Report Issued by the GIA The GIA set the standard for diamond grading and gemological identification, and their grading system serves as the international gem and jewelry industry's benchmark credentials.
Diamond Characteristics Documented in the Diamond Grading Report Shape and Cutting Style: The diamond shape and cutting style.
Measurement: Lists the diamond's dimensions in millimeters.
Carat Weight: The weight of diamond listed to the nearest hundredth of a carat.
Color Grade: A grading which assesses the absence of color in a diamond.
Clarity Grade: Clarity grade determined under 10x magnification.
Cut Grade: A grade of cut as determined by a diamond's face-up appearance, design and craftsmanship.
Finish: Grades that represent a diamond's surface and facet placement. Polish: Rating the overall smoothness of the diamond's surface.
Symmetry: Measuring the shape, alignment and placement of the diamond's facets in relation to one another as well as the evenness of the outline.
Fluorescence: Color, and strength of color when diamond is viewed under UV light.
Comments: A description of additional diamond characteristics not already mentioned in the report.
Clarity Plot: A map of the approximate size, type, and position of inclusions as viewed under a microscope.
Proportion Diagram: A map of the diamond's actual proportions. Reading a Proportion Diagram Proportion diagrams will typically include the following information:
Depth: The height of a gemstone measured from the culet to the table.
Table: Located at the top of the diamond, the table is the largest facet of a diamond.
Girdle: Range of girdle thickness.
Culet: Appearance, or lack thereof, of the culet facet.