Achieving the AGS Light Performance Cut Grade

The AGS Performance Cut Grade System uses patented technologies to determine the brightness of a diamond.

This may sound complicated – and yes, a deep explanation includes lots of technical and mathematical details – but here we offer a less in-depth description.

What does a diamond do? What is its nature? What are you seeing when you look at a diamond? The answer is: beauty.

What you see in a diamond is everything in the panorama surrounding the stone. The bright sparkles could be the lights above your head or even from your TV. The darker areas in the diamond could be the shirt you’re wearing or the bookcase against the wall.

The complex pattern of light and dark is a multifaceted view of the surrounding world. As these virtual windows reflect bright lights, the diamond creates dazzling sparkles.

What makes a diamond appear bright?

Diamonds appear bright if the virtual windows point toward the brightest areas of the surrounding world. This idea makes the foundation of the AGS Performance Cut Grade system and is the essence of the “Light Performance Maps” (ASET® maps) included on Platinum DQD® documents.

Where are the brightest areas of the world?

The world is lit from above. Therefore, diamonds with virtual windows pointing toward higher places tend to be brighter than those pointing to lower places, with one caveat – if a virtual window is pointing too high, then it’s your own face you’ll likely see, and not the brighter world behind it. Interestingly, this obscuration effect of your own body and head can create some of the most striking and visually appealing contrast patterns in a diamond. Not only can a diamond’s contrast pattern be visually interesting, it can contribute to the brilliance of the stone by making the adjacent regions in the diamond appear brighter.

AGS Performance Cut Grade System

While the implementation of the AGS Performance Cut Grade system may be mathematical and technical, the underlying ideas are based on easy-to-understand concepts and straightforward observations. Simply put, diamonds appear bright if their cut draws light from the brightest areas of the world.

Additionally, the brightest diamonds exhibit a minimum amount of light leakage and don’t draw too much light from high angles, where the observer’s head can obscure light sources.

While not a complete technical description of the AGS Performance Cut Grade system, these concepts, as well as the others discussed in this section, serve as the big-picture ideas behind much of the AGS Performance Cut Grade system.

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