Setting a Princess-cut Center Stone in a Platinum Mounting with V-Prongs

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.

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.

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.

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.

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