AGS - Ideal?

[sunset522]

Hey all,

I read on a website that all AGS certified diamonds are ''Ideal cut''. Does that mean that they are perfectly Ideal cut and I don''t need to worry about checking the pavilion angle or the table diameter and crown angle? Please let me know.

THanks,
Sandhya.

 

[aljdewey]

Hi, Sandhya...

No, that's not correct. AGS grades whatever diamonds are submitted to them....some have ideal proportions, and others don't. They grade the proportions on a scale of 0 - 10, 0 being the best.

It's perhaps more likely to find well-cut diamonds among those that have AGS reports because AGS/GIA reports are more expensive than other labs, so it wouldn't make sense for vendors to submit run-of-the-mill stones to a more expensive lab. Kind of like putting really expensive MAG tires on a Ford Escort...doesn't make sense.

Further, even diamonds bearing an AGS 0 ranking aren't guaranteed performers. AGS0 is determined by a range of acceptable angles, but performance is determined by the angles in relationship to one another, and there are several combinations of angles that are likely to produce the best results.

That's why it's important to get crown/pavilion angles on any diamond you might consider.

 

[niceice]

Not all diamonds graded by the AGS Laboratory (AGSL) are ideal cut... A diamond is "Ideal Cut" when the overall cut rating is listed on the AGS Diamond Quality Document or Lab Report as having (1) AGS Ideal Polish; (2) AGS Ideal Symmetry; and (3) AGS Ideal Proportions. The diamond would then be listed as "AGS Ideal 0" on the lab report under the Cut Rating section of the lab report located in the upper left hand region of the document.

If the diamond were graded by the AGS as having AGS Ideal Polish, and AGS-1 Excellent Symmetry and AGS Ideal Proportions, then the overall cut rating of the diamond would be AGS-1 Excellent and not ideal cut... For a diamond to be "Ideal Cut" by AGS standards, all three of the factors that contribute to the overall cut rating must be AGS Ideal. If any of the three factors fall below the ideal cut rating, then the overall rating defaults to the lowest graded factor.

Also note that there are degrees of ideal within the classification as ideal cut as understood by those of us who specialize in such things... A diamond with a 35.3 degree crown angle and a 40.8 degree pavilion angle 'may' have ideal proportions, but is not considered to be as ideal as one with a crown angle between 34.3 - 34.8 degrees and a 40.6 - 40.9 pavilion angle from a paper perspective... However, the diamond may be just as beautiful! The trick is knowing how to combine the sections of a diamond to obtain high degrees of visual performance... A steep crown and a steep pavilion angle don't seem to be as visually pleasing as a balanced crown and pavilion angle or a steep crown angle combined with a shallow pavilion angle or vice versa... Punch the numbers into the HCA here on PS for a little added insight into the potential of the diamonds that you are considering from DI.com