AGS Laboratories FAQs

The AGS Laboratories offers diamond-grading services to members of the jewelry industry only. Our diamond grading reports provide consumers by providing documentation of an expert opinion from an unbiased, independent third-party diamond laboratory. We grade loose diamonds. Our standard grading services include the 4Cs of diamond grading: carat weight, color, clarity and cut.

Any diamond shape can receive a diamond grading report, but we only assign an AGS Cut Grade for loose diamonds that are round brilliants, square princess cuts, emerald cuts, oval cuts and cushion cuts, as well as some proprietary shapes.

We also grade fancy brown diamonds with our own Chroma Signature system; learn more here.

To verify an AGS Laboratories diamond grading report, visit our AGS Laboratories Report Verification page. You can verify the information on your diamond grading report matches the information stored in the AGS Laboratories report database.

If your business is in the jewelry trade, we’ll be happy to set up an account. Please see Become a Client. If you’re not in the jewelry trade, please visit an American Gem Society retail jeweler in your area. An AGS retail jeweler may be able to submit the diamond to the AGS Laboratories for you.

If your business is in the jewelry trade, we’ll be happy to set up an account and inscribe your diamond. Please see Become a Client. If you’re not in the jewelry trade, please visit an American Gem Society retail jeweler in your area. An AGS retail jeweler may be able to submit the diamond to the AGS Laboratories for you.

If your business is in the jewelry trade, we’ll be happy to set up an account and provide a replacement document. Please contact us. If you’re a consumer, you can request a replacement document directly from the Laboratory; simply order a replacement report.

You can Find a Jeweler through American Gem Society. Find a Jeweler

For jewelry appraisal you can trust, find a certified appraiser through American Gem Society. Find an Appraiser

A company memo or invoice must accompany each shipment. You can use the carrier of your choice for inbound shipments.

For shipping loose diamonds, list each stone on the memo, along with carat weight and U.S. dollar value. Each diamond submitted must be in an individual diamond parcel paper, and the paper must indicate the weight.

For shipping mounted goods, please clean them before shipping. Be sure to list each item on the memo, along with the carat weight and U.S. dollar value. Each item submitted must be in an individual parcel paper or plastic bag, and the paper or bag must indicate the weight.

We grade loose diamonds. The AGS Laboratories is a trade-only diamond laboratory and only accepts diamonds from jewelers and manufacturers. If you are in the industry, become a client of the laboratory here.

Any jewelry store can sell a diamond with an AGS Laboratories diamond grading report; however, only an American Gem Society member can sell a diamond with a Diamond Quality® Certificate.

The AGS Laboratories screens every diamond for potential treatments like High Pressure High Temperature (HPHT) treatment, fracture filling and laser drilling. The AGS Laboratories will grade an HPHT-treated diamond if the fact of its treatment is disclosed.

The AGS Laboratories does not grade fracture-filled diamonds or diamonds with any other treatment that is not permanent. However, the AGS Laboratories does grade diamonds that have been laser drilled if they’re not set in jewelry.

All treatments are disclosed in the “Comments” section of an AGS Laboratories diamond grading report.

No. The AGS Laboratories provides an unbiased, independent and expert third-party opinion on the 4Cs of a diamond. You should never see an appraisal amount on a diamond grading report. Price of the diamond should be determined by the jeweler, not the laboratory.

Diamond Cut Grade FAQs


The jewelry industry refers to Cut in two ways:

  • As a reference to the shape, style, and faceting of a diamond.
  • How well a diamond is fashioned (e.g., brilliance, fire, and scintillation).

There is much debate in the diamond industry about what constitutes an actual Ideal Cut. An AGS Ideal Cut is a diamond where all the diamond’s Cut quality factors (light performance, proportions and polish and symmetry) exist at the highest possible levels, making the maximum contribution to the diamond’s beauty and value.

The AGS Laboratories uses the AGS Performance-Based Cut Grade system, which is based on the overall performance of a diamond, specifically in the area of Light Performance. When analyzing the overall performance of the diamond, we take the following into consideration: light performance (contrast, leakage, dispersion and brightness), proportion factors (girdle thickness, culet size, weight ratio, durability and tilt), and finish (polish and symmetry).

In 2006, the American Gem Society released its fancy shape Cut Grade research, which concluded five years of research by a team of diamond experts, optical physicists and mathematicians. Currently, the AGS Laboratories grades princess, emerald, oval, cushion shapes, as well as others. The cut grade system is flexible; it can support a plethora of patented and proprietary shapes never seen before in the industry.

To learn more about the definitions of common cut-related terms please visit the Glossary.


Clarity is the degree to which a diamond is free from inclusions and blemishes. Inclusions are internal characteristics; blemishes are external characteristics. Many diamonds have Clarity characteristics that can be seen only with magnification. The Clarity grade is subjectively based on the nature, location, size, quantity and relief of the inclusions. At the AGS Laboratories, a minimum of two experienced diamond graders grade each diamond for Clarity.

Color normally refers to where a diamond’s Color falls within the range from colorless to light yellow or light brown. At the AGS Laboratories, the Color of a diamond is determined by at least two experienced color diamond graders using a set of master diamonds.

Each diamond grader is required to pass the Gemological Institute of America (GIA) Diamond and Diamond Grading courses. In the AGS Laboratories, several Certified Gemologists oversee the work of each diamond grader.

A minimum of two (2) diamond graders must analyze and agree on each diamond factor.

Yes! At this time the AGS Laboratories grades brown fancy colored diamonds only; learn more about our brown diamond grading system.

Product FAQs

The AGS Diamond Quality® Document (DQD) is the world’s leading diamond report for Cut, and the first one offering a performance-based cut grade for the round brilliant as well as for fancy cuts, including princess, oval, emerald and cushion-shape diamonds. The DQD also provides a complete grading analysis of Color, Clarity, and Carat Weight. We examine the performance of a diamond — how it handles and refracts light. With the DQD, diamonds can receive a Cut grade up to AGS Ideal.

The AGS DQD also is available in the Platinum DQD format. This format provides the same detail as the DQD; it also includes a light performance map based on patented AGS ASET® technology.

The AGS Diamond Quality® Report (DQR) offers a complete grading analysis of a diamond, including the profile with measurements and a custom plot. The Diamond Quality® Report provides an option for diamonds that have less-than-ideal grades on Cut, Polish or Symmetry. Therefore, the maximum grade available on the DQR is AGS 1 (Excellent).

The Diamond Quality® Report (DQR) can be printed for any diamond shape and is available with or without the AGS performance-based cut grade.

The AGS Laboratories proportion-based Gold Diamond Quality® Report (DQR) is based upon the patented AGS light performance system and provides a proportion-based Cut grade.This report can be printed for any diamond shape. The Gold DQR report offers a complete grading analysis of the 4Cs: Cut (standard round brilliant), Color, Clarity, and Carat weight and features word descriptors ranging from Ideal to Very Poor, so that it gives a clear, concise explanation of the diamond’s quality.

The Diamond Quality® Analysis (DQA) is a pocket-size document for stones weighing up to 1.99 carats. The DQA offers a complete grading analysis, without a plot, and includes one required laser inscription for diamond identification. With the DQA, diamonds can receive a Cut grade up to AGS Ideal.

The AGS Diamond Quality® Certificate (DQC) is a diamond grading report available exclusively for American Gem Society retail jewelers.

The DQC provides a complete diamond grading analysis of the 4Cs: the diamond’s Cut grade, Color grade, Clarity grade, and Carat weight, as well as the light performance map (AGS ASET® image).The DQC comes in a high-quality presentation folder and is not laminated, so the AGS titleholder may sign the certificate, ensuring this diamond is certified and of the highest quality.

The AGS Diamond Consultation™ (DC) is a product for diamonds weighing 4.99 carats or less and provides Shape, Weight, Clarity and Color information about the diamond, as well as a plot of the diamond inclusions.The DC provides, in a compact credit-card size fold-over document, a concise snapshot of a diamond for easy identification.

 For more information about individual documents please visit our documents.

Using a microlaser beam, the AGS Laboratories may inscribe the assigned AGS number, brand logos, and messages on the girdle of a diamond. Laser inscription does not damage the diamond nor does it affect the Color or Clarity. The laser inscription can be viewed with a jeweler’s loupe.


Have a question that’s not listed here? Contact us at AGS Laboratories.