AGS Laboratories Will Grade Type IIA Diamonds

AGS Laboratories announced that they will resume grading Type IIa and Type IaB diamonds. Because these two types of diamonds can be high pressure, high temperature (HPHT) treated in order to improve their color, sophisticated testing is required to detect if treatment has taken place, the lab said in a release.

AGS Labs stopped grading for these two types of diamonds in late 2005. The lab said it wants to review advanced treatment techniques and available methodologies for detecting them. As a result of the review AGS purchased additional equipment and reported that it has performed in-depth testing to ensure that HPHT treated stones can be accurately identified. 

As part of the new process for grading treated diamonds, AGS Laboratories will add comments to their diamond documents under three scenarios:

When the owner of a diamond discloses that the stone has been HPHT treated, after testing to verify the accuracy of the statement, it will add in the comments section of the document: “The client has disclosed that this diamond has been high pressure, high temperature (HPHT) processed to improve its appearance.”

In the second scenario, if the owner of the diamond has not disclosed treatment, if evidence for treatment has been detected, the lab will include this comment, “This diamond appears to have been high pressure, high temperature (HPHT) processed to improve its appearance.”

In cases when the lab cannot conclusively determine through testing that a diamond has been HPHT treated, AGS will include the following comment, “Industry standard testing was inconclusive as to whether this diamond has been high pressure, high temperature (HPHT) processed to improve its appearance.”

“AGS Laboratories wanted to ensure that we had researched the issue of grading these type of treated diamonds thoroughly before we went any further in issuing reports on these type of stones,” says Peter Yantzer, executive director of AGS Laboratories.