The Gemological Institute of America, better known as the GIA, offers a Diamond Grading Report, a Diamond Dossier, a colored diamond grading report, a colored diamond identification and origin report, as well as synthetic diamond grading reports.
GIA Diamond Grading Report
The GIA’s Diamond Grading Report includes an assessment of a diamond’s 4C’s – color, clarity, cut, and carat weight – along with a plotted diagram of its clarity characteristics and a graphic representation of the diamond’s proportions. For standard round brilliant cut diamonds falling in the D-Z color range, the report also includes a GIA Cut grade.
The GIA Laboratory issues diamond grading reports for loose, natural diamonds in the D-Z color range that weigh 0.15 carats or more. GIA Diamond Grading Reports are not issued for synthetics, simulants, mounted diamonds or those that have undergone unstable treatments, such as fracture filling or coating. And while reports may be issued for diamonds that have been laser drilled or HPHT processed, these stable treatments are prominently disclosed on the report.
GIA Diamond Dossier
The GIA Diamond Dossier offers the same grading information as the GIA Diamond Grading Report but without the plotted diagram. As an added security feature, the Dossier service includes a microscopic laser inscription of the report number on the diamond’s girdle.
The GIA Laboratory issues the Diamond Dossier for loose, natural diamonds between 0.15 and 1.99 carats, in the D-Z color range. The Diamond Dossier is not issued for synthetics, simulants, mounted diamonds, diamonds that have undergone unstable treatments such as fracture filling or coating, or those that have been HPHT processed. Any evidence of other treatment is prominently disclosed in the report.
GIA Colored Diamond Grading Report
The GIA Colored Diamond Grading Report provides a full quality assessment of a colored diamond including the colored diamond color grade, color origin (natural or treated, such as HPHT processed or artificially irradiated), carat weight, clarity, and a plotted diagram of its clarity characteristics.
Unlike GIA’s D-to-Z color grading system, which is based on the relative absence of color, colored diamond color grading is based on the presence of color. Using a controlled viewing and lighting environment and a comprehensive set of color comparators, trained graders consistently determine the characteristic color of a diamond and assign a color grade (“pink,” for example). The hue chosen is modified by a “Fancy-grade” term, such as Fancy Light, Fancy, Fancy Intense, Fancy Deep, Fancy Vivid or Fancy Dark, which describes the combined effect of tone and saturation.
The Laboratory issues this report on loose, natural colored diamonds weighing 0.15 carats or more. The GIA Colored Diamond Grading Report is not issued for synthetics, simulants, mounted diamonds or those that have undergone unstable treatments, such as fracture-filling or coating. Any evidence of other treatment is prominently disclosed in the report.