Diamond Certification Guide

The 3Ws of Diamond Certification

  • What
    Commonly known as a diamond certificate, a Diamond Grading Report is an official evaluation of the various distinctive qualities of a diamond. Each diamond contains its own figurative "DNA", which is comprised of the diamond's measurements, clarity, symmetry and a handful of additional characteristics. The Diamond Grading Report manifests as a document providing a certified analysis of the distinctive qualities of a single, specific loose diamond. Diamond Grading Reports typically include an exclusive Report Number, a Laser Inscription Registry Number, and unique Security Features.   

  • Why
    You should never accept a diamond without a Diamond Grading Report. This report serves as a testimony to the quality and authenticity of the diamond you are about to purchase. Don't be shy, this is your investment. If it's not offered to you, ask for it. If it's not provided, walk away.

  • Who
    Today's industry leaders in diamond grading reports include the Gemological Institute of America (GIA), the American Gem Society (AGS) the European Gemological Laboratory (EGL), and the International Gemological Institute (IGI). They employ certified gemologists as well as certified diamond graders to conduct thorough, consistent laboratory examinations on the diamonds submitted to them for evaluation. Click on the associated links to access their websites for further information and to view samples of Diamond Grading Reports.

The Gemological Institute of America - GIA

The GIA is the largest American-based non-profit organization in the world, dedicated to diamond education, research, and assessment. The GIA introduced diamond certification to the industry in the 1950's. Since then the GIA's International Diamond Grading System™ has become the most highly regarded international standard for diamond grading. Among the handful of lab reports and services that the GIA offers are the two post commonly issued documents; the GIA Diamond Grading Report and the GIA Diamond Dossier.

GIA Diamond Grading Report®: Commonly referred to as a diamond certificate, the GIA's official name for this lab assessment is a Diamond Grading Report. For those loose diamonds that weigh 1.00 carat and above, the GIA issues a full Diamond Grading Report. This report analyzes not only the stone's carat weight, color, clarity and cut grades, but also marks the stone's inclusions and blemishes using standardized symbols plotted on the diagram. Because no two stones are ever exactly alike, a plotting of the clarity characteristics of a stone serves as a fingerprint in case the stone is stolen, lost or resold.

GIA Diamond Dossier®: For those diamonds weighing under 1.00 carat, the GIA also issues a diamond dossier. The dossier certification includes a minuscule laser inscription of the report's serial number along the girdle of the diamond. It evaluates all of the same key qualities as the diamond certificate without a plotted representation of the clarity characteristics of the diamond.

The AGS is an internationally recognized American-based gemological laboratory dedicated to upholding some of the highest grading standards in the diamond industry. Similar to the GIA, the AGS generates assessments for loose diamonds of at least 0.18 carat. The AGS offers several reports, including a Diamond Quality™ Document and a Diamond Quality™ Certificate. These reports are a testament to the authenticity of the diamond's color, carat weight, clarity and cut, which are reported by the AGS using a 0-10 grading system. A diamond graded with a 0 cut is considered to be an AGS Ideal® Cut, a term that has come to describe the diamond industry's most exclusive diamonds.

American Gem Society Laboratories - AGS

The AGS is an internationally recognized American-based gemological laboratory dedicated to upholding some of the highest grading standards in the diamond industry. Similar to the GIA, the AGS generates assessments for loose diamonds of at least 0.18 carat. The AGS offers several reports, including a Diamond Quality™ Document and a Diamond Quality™ Certificate. These reports are a testament to the authenticity of the diamond's color, carat weight, clarity and cut, which are reported by the AGS using a 0-10 grading system. A diamond graded with a 0 cut is considered to be an AGS Ideal® Cut, a term that has come to describe the diamond industry's most exclusive diamonds.

The International Gemological Institute - IGI

Established in 1975, The International Gemological Institute (IGI) is the largest independent laboratory which provides diamond and fine jewelry grading and evaluations.The IGI prides itself in being the only international certification laboratory which is owned and controlled by one central governing body to ensure consistency in its grading reports worldwide.

Located in numerous cities around the world including Antwerp, New York, Hong Kong, Mumbai, Tokyo, Bangkok, Dubai, Toronto, Los Angeles, Tel Aviv and Cavalese, the IGI issued more than one million reports per year. These reports include diamond grading reports, colored stone reports, identification and appraisal reports and diamond authentication and attestation of origin.In addition to certified grading reports, the IGI also offers laser inscription services,diamond appraisals and diamond and colored stone courses through IGI's School of Gemology.