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Diamond 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 emerald, 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.
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