Colored Gemstone Jewelry Design and Repair

Ask a skilled bench jeweler whether a popular jewelry design can be made with a colored stone, and the odds are you'll receive an affirmative answer. Ask that same jeweler whether it should be made, though, and you may get a very different response.

An experienced bench jeweler will often be able to create almost any design that doesn't actually violate the laws of physics. But colored stones are softer and typically less durable than diamonds, and a setting designed for a diamond may spell disaster with an opal or an emerald. The resulting creation may be beautiful when you first present it to the customer, but if the piece is worn frequently, it's likely to make a quick return to the jeweler's bench for repair.

"With colored stones, a designer and retailer should very seriously take into consideration issues of design and structural integrity before they decide to sell a piece," says Gary Dawson, owner of Goldworks Jewelry Arts Studio in Eugene, Oregon. "There are very few things I will refuse to do, but I always really discuss [with the customer] what they're looking at. For example, I have put tanzanite into rings, but I discuss with [the customer] the liability of doing that and discuss their lifestyle. If they're a landscaper and they want to wear the ring all the time, I tell them this is foolish."

Whether you're creating custom designs or selecting finished colored stone jewelry for a retail store, it's worth considering the long-term prospects of the piece. A well-made piece of jewelry is less likely to present problems during normal wear and is simpler to repair if it does become damaged. A piece that holds up better translates into happier customers over the long term.

Setting the Stone

In theory, emeralds can be channel set, and opals can be flush set. But in practice, such designs require a jeweler with extraordinary setting skills to pull it off. As bench veteran and trade shop owner David Huffman puts it: "Pavé, channel, flush set — with opals? Yeah, right after I set the rivets in these robin's eggs."

The problem arises when a design combines a relatively fragile stone, such as emerald, opal, tanzanite, or tourmaline, with a setting style that requires putting a significant amount of pressure on the stone, such as a pavé, channel, or flush setting. The pressure required during setting can easily break or chip fragile colored stones, even in the hands of an expert setter. These styles often require significant cleanup after setting the stone as well, which can be difficult if the stone is easily scratched or abraded.

The metal used can also affect the ease of setting a stone, and so can the cut of the stone itself. Stones with uneven or thin girdles, thin points, or significant inclusions where a prong needs to go are more likely to break during setting. "There are stones out there that just aren't setter-friendly," says Bradney Simon, an experienced bench jeweler and president of Bench Media, a publisher of educational materials for bench jewelers. "[When buying colored stones], look at the girdle, the edges, and the points, and think about how you would place a bezel or a prong. And [avoid] stones where the pavilion is so big and bowed out it's nearly impossible to get it into a mounting."

And the channel-set emeralds? "Setting emeralds in channels is possible, but very masochistic," Huffman says. "You get several set, then you break one. Now what? If you've got a laser, you can dig out the broken one and weld in a new one and continue; otherwise you're stopped. Please, Mr. Retailer, don't sell custom jobs like this. You are either going to make a jeweler miserable, disappoint your customer, or both."

Once a stone is successfully set, it must still stand up to everyday wear. If a setting leaves a gem vulnerable, the customer may soon be back with a chipped or broken stone. "The big thing I see is softer stones, such as tanzanites and opals, that are set up high, particularly in rings," says Simon. "These stones just won't take abuse; they scratch easily. And if you just set it up there like a diamond, it's going to get bumped every time a person moves."

If a soft colored stone is set in a ring or other piece of jewelry that's likely to receive significant abuse, the design should protect the stone as much as possible. "[You want something that] has design elements that come up higher than where the stone sits and tend to protect the stone," says Dawson. "There are a lot of ways to not necessarily hide the stone in metal, yet design the piece so it will be protected by a design feature."

Can It Be Repaired?

No matter how carefully you design a piece, there's always a chance that one day it will come back to your shop for repair. This is particularly true for rings, which are not only subject to more abuse during normal wear, but are also likely to require resizing as the wearer's finger size changes over time.

One of the classic factors determining how easy a piece is to repair is whether the stones can handle exposure to high heat. Stones that are not vulnerable to heat, such as diamond, ruby, and sapphire, do not have to be removed before the jewelry is soldered, simplifying repair work. Most other colored stones, though, can break or otherwise be damaged if exposed to the heat of a jeweler's torch, and so must be removed before work can be safely done on the piece. In addition, the increasing number of gemstone treatments has made even stones once thought of as safe for heating questionable for the process.

"I really don't believe it's possible to catch all the treatments anymore; there's so much going on in crystal growing and treatments," says 30-year veteran bench jeweler Bruce Holmgrain, who adds that his policy is "anything you're afraid to pay for, don't heat."

Since so few colored stones can safely take the heat of a jeweler's torch, many jewelers routinely remove the stones from their setting for anything but the most minor of repairs. But stone removal also introduces a chance of breaking the stone and increases the time the repair will take, both of which will affect the cost of the repair.

Since stones must often be removed for repair, some designers plan a "back door," which will give them an easy way to take out a stone down the road. Dawson, for example, will leave one prong slightly easier to lift.

For Frederick, Maryland, designer Douglas Zaruba, anticipating repairs is integral to the design of the piece. "When I design a piece, I always consider how I will be able to repair it, should it become damaged," he says. "Since most colored stones must be removed for repairs, I have gone so far as to lock valuable gemstones into the mounting with invisible screws, often hidden behind small stones. I can remove the tiny stone, loosen the screws to remove the gemstone, and work on the piece without worry."

If the jewelry piece isn't designed with repair in mind, it may become necessary to rebuild the entire piece. "If you have stones all the way around the ring, it can make sizing totally impossible," says Daniel Spirer of Spirer Somes Jewelers in Cambridge, Massachusetts. Other problems he cites are heavy bezels on light shanks, or very lightweight pieces that are likely to be badly damaged when the jeweler removes the stones.

Making The Sale

No piece of jewelry can be guaranteed to protect gems from every possible source of damage, and even tough colored stones such as ruby and sapphire can be chipped or broken. But a knowledgeable salesperson can help steer customers toward stones and designs that are likely to last, and which can be repaired if they are damaged.

"If you understand not only the materials, but at least in a rudimentary fashion how a piece of jewelry is put together, it can go a long way to choosing jewelry designs that have structural integrity and the potential for repair," says Dawson.

The first choice when faced with a customer seeking an undesirable design is to suggest alternatives. "People do get particular ideas in mind, and sometimes they just won't work," says Spirer. "We always make very large attempts to talk them out of it. For example, we specialize in fancy-color sapphire, so we always push color-change sapphire to people interested in tanzanite [rings]."

If you can't sway a customer from a less desirable choice of stone or jewelry style, the next best solution is to work with her to design a piece that will protect the stone as much as possible. Gary Dawson suggests having a conversation that goes something like this:

"Mrs. Jones, I love tanzanite, too. They're really beautiful, but they're not the most durable of gem materials, and you need to be aware of that. Tanzanite is a stone that has easily developed cleavages, so it doesn't take much of a shock to break the stone. So perhaps we could consider a design that would tend to protect that stone?"

What if all else fails, and your customer insists on a fragile iolite mounted in a Tiffany-style solitaire, or a ring with channel-set emeralds? Go ahead and sell it, say experienced bench jewelers, but be sure to warn her clearly what the likely outcome of her choice will be.

"As long as you're honest with the customer and tell them what's going on — I haven't had any problems," concludes Holmgrain. "As long as they know what's going on, and they assume the risk, it's not a problem. They get what they want, and everybody's happy."

Colored Stone Do's and Don'ts from the Bench Jeweler

Expert gem setters share their tips — and warnings — for working with colored stones.

Do's

1. Do remove the colored stone before working on a piece unless you are confident it can withstand the heat of soldering and you can afford to replace it if it's accidentally damaged.
2. Do test your pumice wheels and other abrasive wheels on a piece of glass. "If they do not abrade the glass, they will not scratch most faceted stones and would be safe to use cleaning up the prongs," says Simon.
3. Do examine every stone for evidence of treatment, even if it's of a variety that isn't typically subjected to enhancements, and it comes from a trusted source. Custom jeweler Frank Goss of Houston, Texas, notes that he recently was asked by another jeweler to set a 10-carat peridot. Since the stone came from another jeweler, he didn't check it for treatments — until the magnification he used to set stones turned up several anomalies. "I cranked up the magnification on the microscope and surprise, surprise — Opticon! Filled inclusions through the stone, as well as scratches that had been filled," he says. "I thank my lucky stars I saw it before I put the mounting in the ultrasonic or steamer. A very fine trap for the casual and unsuspecting jeweler."

Don'ts

1. Don't coat sapphire or ruby with boric acid to protect the stone during soldering. Although this is common practice with diamonds, heated boric acid will etch the surface of corundum.
2. Don't polish prongs and bezels aggressively when setting colored stones, especially softer stones such as tanzanite. Bench jeweler Bradney Simon suggests coating softer stones with fingernail polish. "The fingernail polish is not hard enough to completely protect the stone, but it will give some protection from abrasion," he says. "More importantly, it will serve as an indicator. If you scrape the fingernail polish off, you are too close!" After setting and polishing, a soak in acetone will remove the fingernail polish. (Simon notes, though, that this trick shouldn't be used on emeralds, where the acetone could remove possible oiling.)
3. Don't put any colored stone in the jeweler's pickle unless you're certain it can withstand acids. (Pickle is an acid bath used to clean jewelry after soldering and other repair processes.) Many colored stones — including turquoise, pearl, and lapis lazuli — can be destroyed by acids.
4. Don't put any colored stone in an ultrasonic or steam cleaner unless you're certain it will not be damaged by these cleaning methods. For example, ultrasonic and steam can strip the oil from a fracture-filled emerald, leaving the jeweler to explain to the customer why their stone looks considerably less attractive than when she left it for repair.
5. Don't let accent diamonds touch a colored center stone. "If one of the diamonds comes loose and rubs against the center stone, it will cut a groove into the stone," warns Simon.

By Suzanne Wade

© Colored Stone – March 2004

In association with