Gem Inlay Jewelry Piece Process

If gem inlay is a simple matter of gluing mineral slivers into metal recesses, why does it take apprentices at Bagley & Hotchkiss Ltd. Three years to learn the basics of this art?

Admittedly, the Santa Rosa, Calif. company, which is one of this country’s best-known makers of gem inlay jewelry, is a bit finicky about fit and finish. But talk to inlay masters at equally fastidious firms like Kabana Inc., Albuquerque, N.M., and Asch Grossbardt Inc., New York, and they’ll give you similar times for becoming adept at the final stages-fitting, grinding and polishing-of this piece process.

And that’s only one phase of inlay jewelry making that requires long training. Before inlayers begin tailoring gem shards for a snug fit in a metal casting, someone has to whittle them from mother rocks. Teaching what inlayers call “slabbing”-sawing rough into usable sections-and “blanking”-cutting down pieces into jewelry inserts-have their own learning curves, especially since many different gem materials, each with its own characteristics, are used.

And before cutting, someone has to buy the rough. Learning how to select the right rocks is a skill that must be acquired. All in all, you’re talking lots of time and lots of people.

This may come as a surprise to jewelers whose only acquaintance with gemstone inlay is intarsia, a purely lapidary form of this art. Since intarsia mainly involves the fitting together of gems to make one-of-a-kind pieces like boxes and pendants, the rough buyer, the lapidary and the inlayer can be one and the same person.

But when the gem inlay process is expanded to make tens of thousands of gem and metal jewelry pieces yearly, you need a segmented work force trained in each aspect of gem inlay jewelry making-from design and casting to cutting and inlaying. Among its 250 full-time employees, Kabana, for instance, has four designers, six lapidaries and 30 inlayers. And with 700 designs in its inlay line, you’re talking of the need for millions of rock shavings.

So the first question to ask of any of the understandably few whose sole trade or main specialty is making such intricate jewelry is why they do it. John Bagley gives as his top reason: “artistic freedom.” “Inlay allows the artist to use color in such a way that his only limit is his own imagination and available materials,” he explains.

For Bagley, inlay permits a degree of interaction between precious metal and precious stone that can be achieved with no other medium. “When I started making jewelry and combining cabochons with metals, I was dissatisfied with the essential separateness of the components,” he continues. “The desire to fuse metal and stone into a sculptured organic whole led me to experiment with the inlay process in the creation of fine gold jewelry.” That was more than 25 years ago, which makes Bagley a pioneer in contemporary gem inlay jewelry.

Of course, there are practical reasons for championing this medium. “Inlaying protects the stone from abrasion and impact blows more readily than conventional bezel and prong settings,” Bagley says. “Gem materials can be cut thinner than in conventional settings without compromising the integrity of the stone and the savings passed on to consumers.”

Given these advantages, gem inlay jewelry is certainly worth the considerable time and effort that go into producing it. But a walk through the steps of its creation will help to explain the relative sparsity of practitioners.

Most companies with inlay lines are faced with the task of finding adequate supplies of the many gem materials they use to give pieces their rich color variety. Hence shopping for rough can require a bit of globe-trotting. Even with an abundance of suppliers on the local Hong Kong market where it manufactures its inlay jewelry, Asch Grossbardt’s buyers have sometimes had to travel to Afghanistan for lapis, Taiwan for coral, the American Southwest for turquoise, the Philippines for mother of pearl, Australia for opal and chrysoprase, Namibia for malachite, South Africa for sugilite and China for jade.

The company’s buyers have little choice but to travel to remote spots in search of rough. According to Bagley, many savvy miners and dealers have gotten wind of inlay’s popularity and are sending agents to America to sell on their behalf. Often these agents pit manufacturers and artisans against each other to get the highest prices for high-grade material. As a result of these bidding wars, inlayers must pay increasingly more for popular gems like opal and scarce ones like sugilite. Sometimes demand is so great that supplies are insufficient. “Purchasing rough is an art by itself,” Bagley says. “The buyer must have a thorough knowledge of market prices, be able to class material as to its value and suitability as well as calculate yields.”

Slabbing of rough is done using a diamond-impregnated circular saw with, in most cases, either a copper or steel blade that is continuously water-cooled to prevent overheating. “The value of the stone depends on the lapidary’s ability to orient and cut the stone to its best advantage,” Bagley stresses. “This is especially critical with gems like opal that can cost several thousand dollars an ounce.”

After slabbing, the material is inspected for imperfections such as cracks and attractiveness in terms of color, pattern or both. Especially pleasing sections of the material are marked for cutting into pieces called blanks and unwanted areas are removed using a trim saw. Next, the blanks are cut into pre-form strips, suitable for inlay, using either carborundurn or diamond wheels or cam followers (similar to key makers). In the case of high-volume production, ultrasonic machines outfitted with cookie cutter-like heads carve out duplicates of themselves by vibratory action.

Now comes the actual jewelry inlay process, during which bits and pieces of various gem materials are inserted into the casting either by free-hand grinding or, in volume operations, with the aid of a mechanical guidance tool called a jig. To make a secure fit, manufacturers either bezel-set the insert into the opening made for it using hammers or burnishing tools or, more commonly, glue the insert in place using epoxy.

After insertion, stones are ground down using water-cooled grinding wheels so they are flush with the surface of the casting and, last, polished using a fabric-covered rubber disc coated with various-grit diamond compounds. It is at this point, says Bagley, that the incomparable end result of inlay is realized: “the fluid flow of gem and gold to create a seamless blend of mineral and metal.”

Modern, March 1995 | 800-759-9997 | (fax) 800-616-9997