Professional Jeweler Archive: Setting Round and Oval Cabochons in Bezels

May 2000

For Your Staff/Defining Quality


Setting Round & Oval Cabochons in Bezels

Knowing how to professionally set round and oval gems in bezels demonstrates another aspect of quality in your shop


Talk to 10 bench jewelers and you’ll hear eight different opinions on how to set a round or oval cabochon in a bezel. In this article, we’ll examine various methods, tips and techniques.

Bezels often are handmade by the bench jeweler to accommodate a particular stone (Professional Jeweler, April 2000, p. 123). When handmaking bezels for cabochon gemstones, bench jewelers need to consider the varying qualities, features and proportions of the individual cabochons they’re using.

Here are procedures suitable for setting a standard-sized cabochon with durable gemstone features, followed by tips for setting a non-standard sized cabochon with somewhat fragile features.

– by Mark B. Mann, Director of Professional Certification, Jewelers of America®

How to Bezel-Set Standard-Sized Durable Cabochons

This step-by-step instruction suits the materials shown below.
1. Prepare the bezel for setting the cabochon by ensuring:
  • There are no filings or other obstructions (like excess solder) on the inside of the bezel.
  • The bezel is high enough to secure the gem, but not too high.
  • The stone fits snugly, is not loose and drops into the bezel without being forced.
2. Use a modified setting burr – a wheel burr – to remove any unwanted obstructions or to increase the bezel’s inside diameter if it’s slightly small for the cabochon. To make a wheel burr, remove the bottom of a setting burr with a bench grinder. Use an abrasive wheel to smooth the bottom, then polish the bottom with tripoli.
Setting burr and wheel burr
3. Prepolish the mounting and assembly. Keep all surfaces flat and even and clean thoroughly.
Wheel burr removes obstructions

4. Place the cabochon in the bezel and select a tool to move the metal over the stone. In this case the bezel is substantial, so a “pushing tool” is used.
This bezel pusher was made from round stock measuring 6mm. The tip was fashioned into a square, and the tip and bottom were polished so the surface will not "scar" the bezel or leave tool marks.
As shown, position the pushing tool against the bezel at about 45° to 50° toward the top of the bezel. Push the bezel toward the stone.
5. Begin by pushing the bezel toward the gem in one location, then rotate to the opposite side and repeat.

6. Now move around the bezel to 90° from the previous location and push that area toward the stone.

7. Finish the preliminary setting process by pushing the metal toward the cabochon in the only area you haven’t done yet.

This is how your bezel should appear at this stage. If the bezel is too high, the indentations will be too severe.
8. Next, carefully push the bezel toward the stone, covering all areas between the previous four setting locations.

9. Carefully complete the bezel-pushing, ensuring full contact between the stone and the metal. You may use a bezel-setting burnisher from the top rim down. Be careful not to slip and cause abrasion to the cabochon gemstone.

Burnishing may or may not be necessary. If you have good and full contact from the pushing process, there’s no need to burnish the bezel. If there are small gaps that just won't “push” against the stone, burnishing is the best way to finish the process.
10. Only minor finish work is required if you are careful with the pushing process. If not, extensive finishing may be required.
Alternatives

Alternatives to a hand bezel pusher are the Foredom #15 and #15D Hammer Handpieces. These are designed to close bezels, move heavy prongs and apply textures and creative finishes. They work best with lighter weight and more malleable bezel material.


Tips for Bezel-Setting Delicate or Fragile Round and Oval Cabochons

1. Some bench jewelers undercut heavy or less-malleable bezels when setting fragile or delicate cabochons, as illustrated below. Be careful not to undercut more than 40% of the bezel’s original thickness because subsequent finishing could cause the bezel to become too weak or even begin to tear at this junction.
2. File a 45° angle on the top.
3. Hammer metal at a 90° angle down from the top using a hammer and punch, the Foredom Hammer Handpiece or the GRS air-driven impact or hammer handpiece systems.
4. To keep the stone from “dancing around,” smear red sprue wax around its edge to hold it in place. Remove the wax after the stone is set.

Contributions by JA Certified Master Bench Jeweler, Jeffrey Mathews of Dallas, TX.

The JA Professional's Guide to Fine Jewelry Craftmanship
Bezel Setting Round and Oval Cabochons

Professionally Bezel-Set Round and Oval Cabochons

A. The bezel terminates at the proper height against the gemstone – high enough to secure it but not so high the gemstone appears “hidden.”

B. The thickness of the bezel wall is sufficient for normal wear; it’s flat, even and consistent.

C. The bezel wall is in full contact with the gemstone.

D. The bezel is highly polished, including the rim around the top.

E. There is no damage to the gem from the setting or finishing processes.

Potential Problems to Watch for

The bezel was “hammered” over the stone; tool marks from the setting process are still evident.
This bezel is too low; normal wear will cause the gemstone to become dislodged and potentially lost.
This bezel wall is uneven in thickness and height. Besides having an overall poor appearance, it poses a security threat to the gemstone.
This bezel wall is not flush against the gemstone. Eventually it will loosen and become dislodged.

Illustrations by Lainie Mann, Visual Communications

© 2000 Jewelers of America Inc.
This information is required for the first and second levels of the JA® Certified Bench Jeweler™ program.

The installments published in Professional Jeweler from February 1998 to July 1999 have been reformatted and published by Jewelers of America as a countertop book titled The JA Professional’s Guide to Fine Jewelry Craftsmanship. To buy a copy, contact one of the following suppliers: Gesswein, GIA Bookstore, Rio Grande and Stuller Settings. Or call JA at (800) 223-0673.


Copyright © 2001 by Bond Communications