AGS and Other Diamond Certificates
Retailers may advertise "Certified Diamonds"and
give various certificates with the stones they sell.
Q: Is ANY certificate better than NO certificate?
A: NO! A diamond certificate is no better than
its author.
The phrase "Certified Diamonds" is advertising hype. Certificates from disreputable or non-existent labs are worthless testimonies. Trust only diamond grading documents that come from a reputable source.
In the March issue we discussed the internationally regarded GIA Diamond Grading Report. This month we'll cover reports issued by the other highly respected diamond grading organization, The American Gem Society (AGS).
AGS offers three documents describing diamonds.
AGS Diamond Quality Report
This is the most complete and most desirable report. It gives all the information listed in the GIA report discussed last month. It uses the GIA's internationally accepted grading system and follows a format similar to that used by the GIA report. That is, the features being measured are described in words.
The AGS Diamond Quality Report also carries information that the GIA certificate
lacks. It is found in the Sarin report — an illustration produced by
a machine that measures the diamond and calculates its proportions.
The Sarin report is similar to the illustration above except that the Sarin drawing reflects the actual shape of the particular diamond being described and, instead of the words crown angle, table, etc., the labels give the actual measurements. So the crucial crown angle and pavilion depth, both missing from the GIA report (see the March 2002 issue), are indeed found on this AGS report. But — the insurer (and customer) must know where to look.
As we mentioned in the March 2002 issue, cut proportions account for about half of a diamond's value. Most diamonds are poorly cut to increase their weight. The diamond-cutting industry pressures labs to conceal this information or to at least make it less obvious. Putting the proportions in the diagram, but not in the word descriptions, makes them likely to be overlooked.
AGS Diamond Quality Document (click here)
This Document uses the AGS color and clarity grading systems, and gives the equivalent GIA grades in parentheses. Each report includes parallel illustrations of the AGS and GIA color scales and clarity scales.
The Diamond Quality Document hides a little more information than the Diamond Quality Report. It doesn't list any of the cut proportions in words but sums things up with an overall cut grade based on the AGS system. However, the savvy insurer (and customer) will know that the important cut proportions are contained in the Sarin illustration.
Diamond Consultation - Unacceptable!
This report has only shape, weight, color, clarity and measurements. It has no cutting information at all and no Sarin report. Since the Sarin report is produced quickly and automatically, the only reason for omitting it is deliberate concealment. Because cut proportions account for half the value of a diamond, a report without this information is unacceptable.
FOR AGENTS & UNDERWRITING
Pay attention to the Sarin report. You might want to draw this information from the illustration to the column at the left, so all relevant data will be together.
GIA and AGS are the most respected organizations for impartially grading diamonds. Other labs may be unreliable or non-existent. As there is no way for you to verify the reliability of other diamond certificates, we recommend that you accept diamond reports only from GIA or AGS.
FOR CLAIMS
Pay attention to the Sarin report on AGS certificates. Use the illustration in this newsletter to locate the crown angle and pavilion depth, and include these with the other measurements you give the jeweler when pricing a replacement. Without cut proportions the jeweler has a lot of leeway. A poorly proportioned stone will be cheaper but may not match the quality of the original; a well proportioned stone may exceed the quality of the original and result in unintended betterment. Giving the jeweler complete information assures an equivalent replacement.
Occasionally diamond certificates are forged. If you suspect a forged report,
use the report number to verify the report with the AGS. Their number is 702-255-6500.
AGS Labs website
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