Quality Assurance Benchmarks highlight workmanship of semi-finished and finished jewelry. Learn how to evaluate the quality of two different platinum settings for a princess-cut center stone.

Perspective view illustration of a platinum princess-cut solitaire ring

The prongs are evenly shaped and brightly polished, and their shape complements the stone’s shape.

Prongs are finished and free of tool marks. The inside of the prongs are finished prior to setting, and the exterior is finished after setting.

There is no flashing of metal at the bearing on any prong.

Close-up view of the mounting of a platinum princess-cut solitaire ring

Prong height, measured vertically from the girdle to the top of the table, is between 90% and 100%.

Prong contact, measured along the crown between the girdle and the top of the table, is 50%.

Small relief cuts keep the stone’s corner points from coming in contact with the platinum prongs.

The platinum prongs’ dimensions are substantial enough to maintain shape during normal wear.

Prong angle is 75 degrees.

Setting Design without Prong Support

Since all princess-cut settings are different, one benchmark may not work for all princess-cut situations. Below is another example with no support between the prongs.

Prongs are evenly shaped and brightly polished, and their shape complements the stone’s shape.

Prongs are finished and free of tool marks. The inside of the prongs are finished prior to setting, and the exterior is finished after setting.

Close-up illustration of the mounting of a platinum solitaire ring

Prong height, measured vertically from the girdle to the top of the table, is between 100% and 110%.

Prong contact, measured along the crown between the girdle and the top of the table, is 40%.

Small relief cuts keep the stone’s corner points from coming in contact with the platinum prongs.

The platinum prongs’ dimensions are substantial enough to maintain shape during normal wear.

Prongs are finished and free of tool marks. The inside of the prongs are finished prior to setting, and the exterior is finished after setting.

There is no flashing of metal at the bearing on any prong.

Prong angle ranges from 60 to 75 degrees.

Potential Problems and Engineering Features

Problems can occur during normal wear if the piece is not made according to quality benchmarks.

Close up cross-section illustration showing the chipped corner of a princess-cut platinum solitaire under the v-prong

If the corner of the stone is in contact with the prong and the ring hits something during normal wear, the stone’s corner can break.

In this example, too much height from the prongs was removed when creating the bearing and finishing the setting.

With impact from the top and insufficient prong contact, the stone could be lost if the prongs are deformed during normal wear.

This mounting is engineered according to Quality Assurance Benchmarks to ensure the piece will last for many years.

Side view illustration of platinum princess-cut solitaire with a bezel-set diamond in the gallery

Dimensions of platinum prongs should be marginally larger than the typical dimensions of prongs made with white gold alloys containing nickel.

The prong angle on this ring is 75 degrees. Steeper, unsupported platinum prongs are prone to distortion during normal wear. Prong distortion makes a stone susceptible to damage or loss.

Lateral support for platinum prongs can come from a gallery wire, decorative element, or in this case, a bezel holding another gemstone.

Perspective view illustration of a platinum princess-cut solitaire

Dimensions of platinum prongs should be slightly larger than the typical dimensions of prongs made with white gold alloys containing nickel.

How-to Video

Setting a Princess-cut Center Stone in Platinum V-prongs

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Featured Quality Assurance Benchmarks

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