American Gemological Laboratories


Certification is a must for Natural Gemstones. Just as GIA is the foremost authority on Colored Diamonds, AGL is the most prestigious laboratory for Natural rubies, emeralds and sapphires. Whether these stones change hands privately, through a dealer or at auction, it is imperative to have an AGL Certificate of Authenticity with the Natural ruby, emerald or sapphire.

The staple of the AGL services is known as the Prestige report. This is a full-page laminated report. The Prestige report is separated into specific parts to make the information presented clearer, with additional comments for each area to provide further information.

The first level of reporting is an identification and Enhancement report. Enhancement detection and disclosure is just as essential to every item submitted to the AGL, as its proper identification. Due to the current situation in the marketplace, where certain gem varieties are routinely treated or enhanced and others are not, as well as the compound nature of many treatment methods today, the AGL breaks up the subject of enhancement into two categories: Standard Enhancement and Additional Enhancement. This allows for the most concise description for the enhanced or unenhanced condition of the gemstone to be presented.


Within this section, the extent of certain treatments, such as clarity enhancement, will be provided using word descriptions, such as insignificant, faint, moderate, etc. In addition, for filling materials used in such gems as emerald, ruby and other gem varieties, the filling material will be identified.

A Stability Index is also provided for information as to the general stability of the treatment under conditions of normal wear.

The second level is the Prestige Origin report. This reporting service provides a determination of the gemstone’s country-of-origin or provenance, in addition to the full Identification and Enhancement of the item. Country-of-Origin services are commonly provided for ruby, sapphire, emerald, alexandrite, and a selection of other gem varieties. This service is not available for all gem varieties.