Tensions mustn’t rise
A tension setting is a dramatic method for holding a gemstone, although there are certain limitations in this style. Cast rings are possible, but I prefer using platinum alloys that can be heat-hardened. It is better to forge and fabricate the metal, since work-hardening vastly increases strength. I worry about rings where the shank is narrower than the diamond’s diameter, as the girdle will be constantly subjected to bumps and stress. And since diamond is harder than any metal, the setting will loosen sooner or later. The other downside of tension setting is the ring needs to be quite thick to provide sufficient strength; not every person has a finger size to comfortably accommodate this much ring. An alternative to true tension setting is channel setting, which allows for a much thinner metal cross-section, as a bearing (a wire or tubing ‘dough-nut’) is placed under the gem and soldered (when the stone is a white diamond) or laser-welded in place. This addition holds the two sides of the channel securely in place. Alternative methods use a solid wire to tie the channel together.
The ring seen in the photo to the left contains two 1-carat round brilliant-cut diamonds that were a gift to my client. She already had similar diamond earrings and wished to have these set in a ring. It took a bit of discussion, since she really wanted this open bypass style, although in the end, I could not convince her to include a connection between the two ends of the ring. Over time, it is inevitable the flex of the ring when it is pushed over her knuckle will eventually cause the ring to break. I tried to mitigate this by using relatively large-diameter fabricated red gold (a harder alloy), while making sure it was annealed to reduce its inherent brittleness. As this will not be an everyday ring, it should serve my client well for a long time.
Pearls are not typically the best choice for an engagement ring or wedding band that will be exposed to normal everyday wear. A client was insistent she wanted a pearl in her wedding ring and I finally ended up with the ring in the photo on the next page. The pearl is a natural abalone pearl, its undulated form and brilliant colour play soft and feminine. However, it was not very thick and I knew it would require extensive support if it was to survive what I anticipate is a long and happy marriage! My solution was to use 19-karat white gold (which is harder and more durable) with a very substantial bezel to set the pearl from behind. The ‘lip’ of the bezel was also quite thick, although contoured to soften the appearance. Initially, I planned the under-support could be made of square wire shaped to conform precisely to the pearl’s underside. However, it was pretty quickly apparent that a solid gold plate would be the best solution. The combination of the bezel thickness and the metal below the pearl created a ‘strong-box’ effect that should prevent most damage to the gem. Its downward curve also reduces the chance of its surface being abraded under normal wear. This is still a ring requiring care when worn, but it managed to meet both the client’s desires and my need to make a piece I could feel good about selling.
A client initially wanted a tension setting for a wedding band featuring a rough diamond octahedral crystal. I thought otherwise. Instead, we compromised by adding a solid plate for the stone to rest on that could be laser welded to keep the channel secure. We had to sink quite a bit of the diamond’s corners into the ring to keep it from wobbling and working itself loose.
