Certification

Before purchasing a diamond, you should expect to review a copy of its certificate as proof that it has undergone an unbiased, professional examination.

A diamond certificate, also called a diamond grading report, diamond dossier®, or diamond quality document, is a report created by a team of gemologists. The diamond is evaluated, measured, and scrutinized using trained eyes, a jeweler’s loupe, a microscope, and other industry tools. A completed certificate includes an analysis of the diamond’s dimensions, clarity, color, polish, symmetry, and other characteristics. Many round diamonds will also include a cut grade on the report.

Every loose diamond sold by Blue Nile has been analyzed and graded by either the Gemological Institute of America (GIA) or the American Gem Society Laboratories (AGSL). These two laboratories are among the most respected laboratories in the diamond industry, and are known for their consistency and unbiased diamond grading systems. Diamonds that are accompanied by these grading reports are the most highly valued in the industry.

In addition to being graded by either the GIA or the AGSL, all Blue Nile Signature Collection diamonds are certified by GCAL. This additional certification provides a second independent and authoritative analysis of your diamond. GCAL also verifies that your diamond meets all of the demanding quality requirements of the Blue Nile Signature Collection diamonds.

If you are interested in a specific certified diamond at Blue Nile, you can view its certificate on our site before purchase. We offer a variety of grading reports and documentation:

If you are interested in a diamond and a certificate is not available for viewing on the site, simply contact a diamond and jewelry consultant at service@bluenile.com or 800-242-2728.

How Does Blue Nile Grade Diamond Cut?

Blue Nile uses cut grades provided by GIA and AGSL whenever these are available. Many diamonds graded by the GIA prior to January 1st, 2006 do not have such grading. If a cut grade is not provided by one of these laboratories, Blue Nile defaults to a proportion system that uses measurements of depth and table to determine the amount of brilliance in a particular diamond’s cut. Learn more about how Blue Nile provides cut grades that allow you to compare diamonds using consistent criteria.