History and Characteristics of Tension Settings

  There is no doubt that the focal point of this solitaire engagement ring is the elegant diamond. Visible from nearly every angle and open to the light on nearly every facet, this half-carat diamond appears to hover within its white gold mounting as if it were a hologram. Designed by GelinAbaci, renowned for their exquisite tension-set fine jewelry, this diamond engagement ring is a pristine example of this spectacular setting. The gemstone is held in place, not by prongs or grooves in the metal, but by two points of spring-loaded compression. While the stone is the central focus of  a tension-set ring, it is the metal that receives the most attention during the crafting stage.

How Do They Do That?

The metal must be malleable, but tough as nails. This rules out many conventional metals, including conventional gold and silver alloys, which are too soft to withstand the pressure. Most tension rings are made from specialized alloys. While these can include yellow gold, platinum and white gold are more typical. These specialized metallurgical combinations are cold-worked, hardened, then heat-treated in order to maximize their strength. Once the metal is perfected, the jeweler will calibrate the shank of the ring to the specific gemstone. This is the most important part of the setting process, as imperfect calibration will lead to failure. Once the measurements are made and the metal is cut to perfection, the band is  then spring-loaded, the gemstone is set in place, and the metal is released to grab hold of the stone. The force pressing against the stone in a tension ring is generally 12,000 pounds of pressure per square inch. This is a tremendous amount of force, which makes it an impossible setting for gemstones with a Mohs hardness of less than 9.0. Even stones of hardness 9.0 or greater must be free of inclusions, as even the slightest bit of weakness in the stone will cause it to shatter under pressure.

History of Tension Rings

Friedrich Becker, an employee at the German-based jewelry firm Neissing, began experimenting with the concept of tension settings in the late 1960s. In 1979, Herr Becker's vision was realized when he applied lateral pressure to hold a diamond between a spring-hardened, 35-gram, 18k-gold (75% pure gold; 25% special alloy metals for strength) ring that hugged the finger like a fat donut. This prototype was adapted by American jeweler and metallurgist, Steven Kretchmer, who patented a solution to the bulky appearance of the tension set rings. In 1987, his platinum alloy "Plat/SK" allowed for a lighter-weight band without sacrificing strength. At the same time, Mr. Kretchmer was experimenting with spring-loading techniques. In 1992, he secured patents for his method of applying spring pressure to his special alloyed metals. Given the technical difficulty and expertise required to craft a true tension-set ring, only a few jewelers have truly mastered the art.

Myths & Knock-Offs

This dynamic mounting style has generated a fair amount of buzz regarding its fragility. With only two points of contact on the gemstone, it appears a risky business for a diamond. Many people wonder, Is my stone really secure? Actually, experts agree that tension settings are just as secure, if not more secure than traditional 4-prong settings. Prongs are made of tiny drops of metal, often out of gold or platinum. Over time, the metal wears down and must be replaced. Sometimes prongs snag on clothing and bend or become misshapen, thereby compromising a gemstone's security. Aside from a direct blow, a well-made tension ring is nearly indestructible. The key phrase here is "well-made". There are many tension rings on the market, and some of them are made with inferior alloys, deficient spring-loading technique, and imprecise gemstone calibration. As you can imagine, a knock-off tension ring is hardly worth the savings you might find in the marketplace. When it comes to tension rings, purchase only from the best. Among them are the aforementioned Steven Kretchmer and Niessing, but also GelinAbaci, Danhov, and MDTdesign, with GelinAbaci leading the pack in world production. With any of these names you can be assured of the fire, brilliance, and security the tension setting has to offer.