A certificate is a blue print of a loose diamond. Wholesalers, retailers, and consumers alike know a certificate as either a diamond grading report or diamond dossier. A certificate will tell a diamond’s exact measurements, weight, cut and overall quality. A certificate will precisely point out a diamond’s individual characteristics as well as be a useful tool in identifying a stone. When shopping for a loose diamond, considering stones that have a grading report will allow you to make a more informed decision on which diamond will be ideal for you.
The Gemological Institute of America, GIA, is the number one, most respected laboratory in the world. Any diamond submitted to GIA is ensured to have reliable and consistent grading. Anywhere from 3-6 separate gemologists will individually grade each and every diamond for an accurate final grade. GIA grading reports have been considered to be a hallmark of integrity throughout the diamond world. GIA issues two separate types of reports. One of the more common reports is the full issued GIA document, which will have the full description of the diamond as well as a plotting diagram of the grade setting clarity characteristics of that stone. This report is generally used for diamonds 1.00ct and above. The second type of report issued through GIA is the Dossier, which is typically done on diamonds under a carat. The GIA Dossier will have the full individual details of each diamond graded, however the plotting which is normally seen on a report, has been replaced by a laser inscription registry number. This number has been laser inscribed on the diamond’s girdle allowing for verification of the stone without a mapping of inclusions. This has allowed GIA not only to save money on issuing full reports on smaller diamonds but has also saved the time required in plotting a stone’s diagram.
The American Gem Society Laboratories, AGS, is known through out the diamond industry as grading top-notch ideal cut round diamonds. Their high standards surpass those of any other grading laboratory when considering color and clarity as well as cut. If a diamond has been graded by AGS Lab, it has met the standards of what is considered the perfect proportions, polish, and symmetry; and has been given a grade of “ideal” or a “000” rating. AGS Ideal cut round diamonds are highly sought after in today’s market.
Though the European Gemological Laboratories, EGL, all share the same name, they are owned and run independently of each other. Standards vary.
EGL USA (New York and Los Angeles) – Grading from this laboratory does not meet GIA and AGS grading standards. Uses the SI3 clarity grade. Stones may be graded higher than they really are.
EGL ISR (Isreal) – Grading from this laboratory has been found to be lax, and stones do not meet GIA and AGS grading standards. Uses the SI3 clarity grade. Stones may be graded as many as two grades higher than they really are.