Menu
Professional Gemological Identification Services
The Accredited Gem Lab® (AGL) designation means the firm you are shopping with has the minimum equipment required to perform gemological testing and appraisals. The equipment includes a gemological darkfield binocular microscope (essential for gemological observations), a master color grading set per American Gem Society (AGS) Standards (for reliable color comparisons of diamonds), a gemological library of reference materials, and more.
Firms with the Accredited Gem Lab® designation prove to their customers and clients they are vested in the thorough inspection of gemstones and jewelry. More importantly, each Accredited Gem Lab® is required to have an AGS titleholder on staff, with a minimum of a Certified Gemologist® (CG) or Certified Gemologist® Appraiser (CGA) title to oversee its use. This ensures that a fully-credentialed gemologist with the proper knowledge is responsible for gemological testing and appraising.
If you are in the jewelry industry and would like to learn more about how to qualify for an AGL designation, please click on the sections below or contact [email protected].
The following requirements must be met for a firm to qualify as an Accredited Gem Lab (AGL). These requirements will be reviewed and updated based on current needs and technological developments. Please note that these requirements must be met by a Retail or ICGA firm member holding or applying for the AGL designation:
It is also recommended, but not required that the firm have:
An Accredited Gem Lab® must be operated in a professional and ethical manner, in accordance with the Membership Standards of the American Gem Society. Any member who operates a laboratory in such manner as to bring discredit upon the Society, by unwarranted discrediting of a competitor’s merchandise, or by any other unethical conduct, shall be subject to probation, suspension, or expulsion from the Society or any other action recommended by the Grievance & Review Subcommittee.
An Accredited Gem Lab® is subject to audit without notice for compliance for the above elements. If the audit identifies non-compliant elements, the titleholder that oversees the AGL (AGL Principal) will have one (1) year from the date of Notice of Non-Compliance to rectify any issues that would cause non-compliance.
To qualify as an Accredited Gem Lab® (AGL), a set of at least five (5) diamond color masters is required. Color master diamonds must be graded by GIA or AGS Laboratories as master color grade diamonds, and must satisfy the following requirements.
REQUIREMENTS
Color: The first diamond must be AGS 0.0 (D), AGS 0.5 (E), or AGS 1.0 (F). Each additional diamond can have no greater variation than one (1) numerical AGS color grade or the second GIA letter grade from the previous diamond. For example, if the first color master diamond is an AGS 0.5 (E), the next diamond must be an AGS 1.0 (F) or AGS 1.5 (G). Single or split grades may be assigned according to the Colorimeter Conversion Table under “AGS Colorimeter Values” if the diamonds were previously graded at AGS Laboratories.
Color Scale:
Fluorescence: Master diamonds must not have visible fluorescence. Since fluorescent diamonds can vary in color grades between daylight and artificial light, they are not appropriate color masters. In colors lower than AGS 3.5 (K), faint fluorescence may be accepted.
Cut: Diamonds should conform to the same general proportions. Due to differences in depth, there can be variations in the appearance of color in a shallow diamond compared to a deeper diamond. This can make accurate comparisons more difficult. All diamonds in the set should be approximately the same size and proportions.
Clarity: Slightly included diamonds are acceptable, providing that the characteristics do not affect the color or transparency of the diamond.
Weight: Diamonds must weigh 0.25 carats or more and must be unmounted. It is recommended that the diamonds in the master set are within 0.10 carats of each other. This size is adequate for comparison of diamonds up to 1.00 carat.
Girdle: Diamonds must have polished or faceted girdles and there should not be large girdle thickness variations from one stone to another.
Laser Inscription: Each Color Master Diamond must be laser inscribed as an identifier to ensure there are no possibilities of mistaking a master diamond for a diamond being assessed. The inscription must be the GIA color master inscription or the AGS number, estimated Colorimeter value, and the equivalent master color grade.
The following table outlines the recommended standards for laboratory-grown diamond screening and detection equipment needed to qualify as an AGS Accredited Gem Lab®.
| Diamond False Positive Rate | Ratio of laboratory-grown diamonds and diamond simulants incorrectly classified as natural diamond to the total number of laboratory-grown diamonds and diamond simulants | 0% | |
| Referral Rate | Ratio of natural diamonds being referred for further testing to the total number of natural diamonds | 5% or less | |
| Diamond Accuracy | Ratio of natural diamonds correctly classified as natural diamonds to the total number of natural diamonds | 95% or more | |
| Laboratory-grown Diamond Referral Rate | Ratio of laboratory-grown diamonds being referred for further testing to the total number of laboratory-grown diamonds | 100% if listed | |
| Diamond False Positive Rate | Ratio of laboratory-grown diamonds and diamond simulants incorrectly classified as natural diamond to the total number of laboratory-grown diamonds and diamond simulants | 0% if listed | |
| Referral Rate | Ratio of natural diamonds being referred for further testing to the total number of natural diamonds | 5% or less, (recommended) | |
| Diamond Accuracy | Ratio of natural diamonds classified as natual diamonds to the total number of natural diamonds | 95% or more | |
| Laboratory-grown Diamond Referral Rate | Ratio of laboratory-grown diamonds being referred for further testing to the total number of laboratory-grown diamonds | 100% if listed |
The above recommendations are based on key metrics used for the testing of diamond verification instruments by Project ASSURE. The results of all instruments tested are available in the ASSURE Directory. When choosing a diamond verification instrument to purchase, please visit the ASSURE Directory to help make a decision based on the accuracy metrics listed for each instrument. Project ASSURE provides a third party assessment of all instruments submitted.
For the most up-to-date information, please visit the ASSURE website at naturaldiamonds.com/council/assure-diamond-verification. Testing is ongoing on new equipment and the instruments list on the ASSURE Directory may be updated from time to time.
Do you meet the requirements to become an Accredited Gem Lab® (AGL)? If so, apply today by completing this application and submitting to [email protected].
Questions? Contact membership at [email protected] or 866.805.6500, option 3.
Copyright © 2023 American Gem Society