What is a GIA Diamond Grading Report?

Diamond GIA Report
Worthy Staff

By Worthy Staff | Aug 23rd, 2017

So you’ve decided to sell a diamond. You may know how much you bought it for, and be aware that, much like a car, the resale value isn’t going to be as close to the amount you paid for it as you’d like it to be. You might even have a report from you jeweler or a grading lab that details the quality of your stone, but how can you figure out how much it’s really worth? And if you’re not sure what it’s worth how do you know a buyer isn’t taking advantage of you? This is exactly why we created Worthy: we saw a need for a service that allows consumers to reach the wholesale buyers that specialize in pre-owned jewelry with a team of diamond experts (that’s us!) advocating for them and their stone.

One way that we insure you are getting the best possible deal is by providing a complimentary grading from GIA. We wrote this article to explain why buyers trust the GIA name more than any other grading lab out there. It is well known among members of the diamond industry that grading reports can vary drastically, and GIA is recognized as an authority by the kinds of buyers you want bidding on your item. We asked our Chief Gemologist, Roy Alberts, to share his expertise with us, so, here it is, everything you need to know about how GIA determines the quality of a diamond and why we at Worthy provide these reports to our sellers.

A diamond grading report documents the specific characteristics of a diamond. It is important to recognize that many stores will issue their own documentation and diamond reports that are graded by in-store gemologists, some of whom may have been educated and trained by GIA – the Gemological Institute of America. For example, Tiffany & Co issues their own exclusive grading report, as does Zales. However, only GIA can issue a GIA grading report.

GIA, a nonprofit organization, is a public benefit research and educational institution and acts as an independent and impartial entity for evaluating the quality of diamonds and gems and delivering unbiased information. GIA does not sell diamonds or gemstones, nor does it represent the interests of any retailers or sellers.

A GIA Diamond Grading Report is your assurance that your diamond is a natural diamond, with disclosure of any treatment to enhance color or clarity. The report provides the kind of clear evidence that is vital to a confident purchase. (Source: GIA)

The grading reports issued by GIA (Gemological Institute of America), are recognized as the most respected and impartial reporting in the diamond industry. With objectivity and expertise as its hallmarks, GIA ensures the integrity and accuracy of every grading report it issues. A report from GIA is an expert, un-biased statement of a diamond’s identity and quality characteristics.

A GIA report isn’t an appraisal of financial value; rather it is an assurance of the diamond’s quality, with clear disclosure if the material is natural, synthetic or treated to enhance or alter its appearance. The report provides the kind of evidence that is vital for understanding and evaluating a diamond so as to be able to make a confident diamond sale.


GIA tests every diamond submitted to determine whether it is natural, a synthetic or simulant, and discloses any treatments discovered during the examination. Having a GIA diamond grading report accompanying your stone is a comprehensive, methodical and scientific evaluation of the qualities that contribute to a diamond’s overall value. These credentials enable people on both sides of any transaction to operate with confidence, knowing GIA has issued the grading report on a diamond.

Worthy recognizes the importance of impartial reporting and objectivity in evaluating precious stones and offers a complimentary GIA diamond grading report to each customer.

Top 3 Reasons Worthy has chosen to use GIA diamond grading reports:

Standards: GIA has established the worldwide standards for diamonds. GIA developed and maintains the methods and best practices for evaluating diamonds worldwide. As creator of the 4Cs of diamond quality and the GIA International Diamond Grading System™, GIA established the common language for describing the quality of D-to-Z color diamonds.

Diamond Clarity

Accuracy and Consistency: Every GIA laboratory operates under the same set of standard procedures and principles designed to ensure the objectivity and accuracy of every gem identification or grading report issued. These tenets are supported by research, highly trained staff, robust quality control systems, and a suite of best-practices.

Protect: Through research, education, and unbiased gem grading and analysis, GIA strives to protect the gem and the jewelry buying and selling public by setting, adhering and maintaining the diamond global quality standards.

What’s Included in a GIA Grading Report?

GIA’s diamond grading reports evaluate a diamond on each of the characteristics that are most relevant to its overall quality. Since 1953, when GIA first began grading diamonds based on its 4Cs standards, the Institute has been globally renowned for its diamond grading reports, available in both a hard-copy version and more recently as a digital only electronic report.

GIA Report

Source: GIA

The GIA 4Cs of Diamond Quality:

Source: GIA
Source: GIA
Source: GIA
Source: GIA

Completing the Picture: GIA’s Other Measurements

In addition to the 4Cs, there are other characteristics identified in the report that tell a person more about the diamond that they’re viewing. Fluorescence is one of the other distinguishing characteristics that is determined by the diamond’s ability to emit a glow of a certain color when exposed to UV light. A very small percentage of diamonds exhibit fluorescence. The fluorescence scale begins at none, and runs through faint, medium, strong, and finally, very strong.

A GIA report shows a diamond’s measurements and shape. Measurements are found using complex equipment and the shape is determined by grader analysis. Additional grading information found on the report includes the polish and symmetry of the stone. Polish evaluates the smoothness of a diamond’s surface and symmetry is the evaluation of the alignment of the stone’s facets, outline, placement and shape. Polish and symmetry are graded using the range Excellent to Poor.


There is also a comments section in the report, which notes specifics about other characteristics that may have been observed during grading. Comments can cover such features as a unique blemish, and may include more details on how a diamond may have been treated to improve clarity , or other relevant pieces of information.

Additionally, inscribing a diamond is a modern, effective way for one to identify it without accompanying paperwork. With a microscope, one can usually manage to find where the stone was laser-inscribed with its identifying information.

GIA Protects the Gem, the selling and buying public and retailers alike.

A GIA grading report is an unbiased analysis using established global diamond standards with the ultimate goal to protect the public, the buyer and the seller, be it the newly engaged, the divorcee, as well as the jewelry stores and buyers.
There are additional elements contained within the report that further this notion. The system that GIA uses to store diamond measurements and identities is vast, and each stone is denoted by a specific GIA report number. This number is displayed at the top of the report, and is used to reference your stone’s online listing. Diamond sellers can use this to show prospective buyers that their desired stone has been closely scrutinized by professionals and characteristics are stated accurately.


The report also has a QR code at the bottom, which can be scanned by a smartphone, and sends the viewer online to GIA Report Check, which displays the report information for the gem in question. These measurements more often make a GIA report a non-negotiable addition to any trade or sale. GIA’s efforts at achieving meticulous accuracy for every stone they inspect help make the industry safer as a whole by preventing fraud. Anyone with any amount of experience can rely on a GIA report to speak for itself in any negotiation, but comprehension of the report’s finer details is recommended.


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