The Gemological Institute of America - Gem Trade Lab
This is referred to as either the GTL, or a GIA "certificate." GIA education remains the industry standard for Gemologists. A Graduate Gemologist is the highest title the Institute can give. The Gem Trade Lab report is not actually a "certificate" though it is often called one. The report contains several "facts" along with what is mostly opinion. The facts are the date it was examined, the measurements and the weight. Everything else on the report is an opinion, subject to the very aggressive fine print written on the reverse side of the report.
The American Gem Society Lab
This newer lab distinguishes itself by its cut grade. The American Gem Society is an association of retail jewelers and wholesalers, different from the lab which operates under a separate board of directors. AGS and the GIA are sister organizations but the lab compete directly. The AGS lab reports contain the same facts as the GIA report. Everything else is an opinion. The AGS and the GIA are generally considered the most conservative in grading color and clarity and they are usually within one grade of each other. They hold to a standard of consistency of one grade clarity and two grades in color for a diamond submitted twice at different times to the lab.
This lab was launched by Don Palmieri and remains the only lab to be ISO accredited. This lab is also known to be conservative on their grades for color and clarity, and boast of being consistent with the GIA lab. Their cut grade parameters are somewhat broader than AGSL.
This lab operates under many franchises both in the United States as well as overseas. The grades for color and clarity are not as consistent in our opinion among the franchisees. It is one of the most common reports. Often times diamond cutters will "shop" reports, sending their diamond to many labs looking for the most lucrative report.
Passion Fire Diamonds has all the equipment necessary to confirm various grading reports. We rely on the various labs to confirm our opinions of color and clarity, but we always use our own opinion for color and clarity for the final determination before we ship a diamond to a client. Every Passion Fire diamond has been personally examined by a Master Gemologist Appraiser.