Founded in 1931, the Gemological Institute of America (GIA) is an independent, non-profit organization widely considered as the world's foremost authority in gemology. Introduced in 1953, their diamond and gemstone grading system is recognized as an accepted standard worldwide. Gemstone manufacturers from around the globe send diamonds and gems to the GIA for expert examination and analysis.
The GIA's mission is to increase consumers' trust in diamonds and jewelry by upholding the highest standards of integrity, academics, science, and professionalism. They work toward this goal by providing jeweler and consumer education, conducting meticulous research, and developing state-of-the-art laboratory instruments for diamond inspections.
Diamonds graded by the GIA are examined by a minimum of four highly trained diamond graders and gemologists. At each step of a diamond's evaluation, a more senior staff member independently grades the stone. To ensure impartial evaluations, the distribution of diamonds to graders is a completely random process.
After a diamond's carat weight is determined, its measurements, depth, table, angles, culet, and girdle thickness are recorded.
A diamond's color is graded on a scale ranging from D (colorless) to Z (light yellow) by comparing it to master stones of predetermined color.
Clarity is assessed on a scale ranging from FL (flawless) to I3 (included) based on an examination of the stone under a binocular microscope of 10x magnification. The stone's characteristics are plotted on a diamond diagram.
Cut grade is established for brilliant round-cut diamonds based on the analysis of the stone's craftsmanship and light interaction. The level of a diamond's craftsmanship is determined by evaluating its polish, symmetry, and proportions. The stone's light interaction is based on its brightness, scintillation, and fire. The GIA designates the quality of a cut on a grading scale ranging from Excellent to Poor.
A diamond is evaluated for polish and symmetry on a grading scale ranging from Excellent to Poor. The grade is based on an inspection of the diamond's craftsmanship.
A diamond's fluorescence is determined as None, Faint, Medium, or Strong based on its reaction to ultraviolet light.
For added security and identification, a diamond's girdle can be laser inscribed with its GIA report number. The GIA offers laser inscription services for all of the loose diamonds they grade.
The GIA has graded some of the world's most legendary loose diamonds, including the 44.5-carat Hope Diamond, which is displayed in the Smithsonian Museum in Washington, D.C.
The GIA Diamond Grading Report is issued for diamonds that fall in the D-Z color range. This detailed report includes a full quality analysis of shape and cutting style, measurements, carat weight, color grade, clarity grade, cut grade (for brilliant round-cut diamonds), polish and symmetry assessments, and fluorescence. The report also includes a plotted diagram indicating the relative size and location of clarity characteristics, a proportion diagram, and GIA grading scales.
The GIA Diamond Dossier® is issued for diamonds between 0.15 and 1.99 carats that fall in the D-Z color range. This report includes all of the information featured in the Diamond Grading Report without a plotted diagram. All diamonds accompanied by a Diamond Dossier are laser inscribed and registered in the GIA inscription registry.