GRADING REPORTS - Understanding a GIA Grading Report
WHAT IS A DIAMOND GRADING REPORT? A diamond grading report or certificate is a certificate issued by an independent gemological laboratory attesting to the characteristics of a specific diamond. Diamond Grading Reports confirm that a specific diamond has been examined by trained and experienced diamond graders who, using gemological instruments, have determined that the diamond contains the characteristics as stated in the certificate.
WHY USE A DIAMOND GRADING REPORT? Diamond Grading Reports have incredible value in providing buyers with an unbiased, professional evaluation of a specific diamonds characteristics. When purchasing a diamond with a certificate, buyers need take the risk of relying on their own "naked-eye" examination of the diamond and paying a price that does not relate to the actual value of that diamond. Each Diamond Grading Report is allocated an exclusive number that corresponds to a specific diamond. In addition, most Diamond Grading Reports will include diagrams illustrating inclusions unique to that specific diamond, providing further proof of certification.
WHAT DOES A DIAMOND GRADING REPORT TELL US ABOUT A SPECIFIC DIAMOND? As a diamond's "blueprint" a Diamond Grading Report provides extensive information on the diamond's precise characteristics, typically including the following:
- Diamond shape - for example round, square, pear, oval
- Measurements - of the diamond's diameter
- Weight - weight is rounded to one hundredth of a carat. One carat is the equivalent of 1/5 of a gram
- Proportions - depth percentage and table percentage are measured.
- Depth is a reference to the percent of the depth of the diamond, measured from table to culet, relative to the width of the diamond.
- Table is a reference to the proportion of the table (top flat part of the diamond) relative to the diamonds average width. Girdle - reference to the thickness of the dividing line between the top and bottom parts of the diamond.
- Culet - indicating the presence of the pointed part at the bottom of the diamond.
- Polish and Symmetry
- Polish refers to the quality of the polish of the facets
- Symmetry refer to the extent of precision that the facets have been aligned with each other.
- Clarity - internal and external clarity of the diamond measured from IF - I3
- Color - the measure of clarity in a diamond measured from D - Z.
- Fluorescence - a diamond's reaction to exposure of UV radiation.
- Plot - an illustrative representation of the diamond's imperfections.