Bezel-Setting Round Brilliant Stones

August 1998

For Your Staff:Selling Quality

Bezel-Setting Round Brilliant Stones

Knowing what to look for when inspecting and taking in bezel-set round brilliants demonstrates an aspect of quality in your shop

by Mark B. Mann
Director of Professional Certification
Jewelers of America

This month we'll discuss seven essential points to consider when taking in and/or inspecting bezel-set round brilliant stones.

 

1. The stone is tight and secure.

An important first step is to inspect, clean and inspect again, each time checking for loose and/or damaged stones. Stones loosen for various reasons; here are some of the most common:

  • During the original setting process, a metal filing was trapped between the stone and the bezel and it has dislodged.
  • The original seat or bearing for the stone was cut too large; metal was burnished over the stone to tighten it, but over time it has loosened.
  • The bezel has "opened-up" through normal wear, loosening the stone.
  • The stone has loosened through excessive wear of the bezel, and the bezel material is too thin to reburnish.

Following are three ways to check for loose stones. (In next month's article, we'll discuss repairing bezels and tightening loose stones.)

 

Jiggle Method

Install a reciprocating hammer hand-piece onto a bench jeweler's flexshaft and operate at high speed. Place the jewelry against the flexible shaft cover, near the hammer hand-piece. If the stone is loose, it will jiggle.

 

Bamboo Probe

Using the pointed end of a bamboo skewer (from the grocery store), push on various parts of the stone to see whether it's loose. The bamboo is soft and won't damage the stone.

 

Sticky Wax

Most bench jewelers pick up stones during setting by placing a type of sprue wax (used in the casting process) or soft sticky wax on the end of a small probe. Stick this wax to the top of a stone and determine whether you can turn or move it.

 Caution: If you find loose stones, check them very carefully for concealed damage before trying to retighten them. If a stone was set in a bezel to conceal a flaw or previous damage, the force required to push metal over the unstable stone to tighten it may cause further damage.

2. The stone is level and even. Simply check this by eye.

3. The facet orientation is "square"with the design.

4. The bezel wall is thick enough to hold the stone securely. For stones up to one-third carat, the wall should be at least 0.50mm; for stones up to 1.50 carats, it should be about 1.0mm; for larger stones, it should be thicker.

5. The thickness of the bezel wall remaining after cutting the stone's seat or bearing is at least 50% of the original width of the metal.

Ideally, the stone sits securely on a seat or bearing cut into the bezel. The bench jeweler then folds metal over the stone to keep it in place. The seat must be the same diameter as the stone; if it's cut larger and metal is then folded over to keep it in place, the stone will loosen quickly. This is an error in workmanship.

6. The thickness of the remaining bezel wall is even and the wall is finished consistently and in full contact with the stone. Because the bezel facets of the stones can "terminate" differently (see box), it's difficult to determine whether the stone has proper contact with the bezel.

7. The stone is not damaged. The facet junctions are not abraded or scratched and there is no other damage to the stone.

Contributions for this article were made by JA Certified Master Bench Jeweler Jeff Matthews of Jeffrey Howard, Dallas. TX.

Illustrations by Lainie Mann

JA Quality Assurance Guide
Bezel-Setting Round Brilliant Stones

Proper Bezel Setting
of Round Brilliant Stones

 

  1. The stone is tight and secure.
  2. The stone is level and even.
  3. The facet orientation of the bezel is "square" with the design.
  4. The thickness of the bezel wall is sufficient to hold the stone securely.
  5. The top portion of the bezel is evenly burnished over the stone.
  6. The top of the bezel is bright-cut or finished evenly.
  7. The stone is not damaged.



Potential Problems When Bezel-Setting Round Brilliants

The stone is not level

If the stone is not level as shown (an error in workmanship), you must remove it and reset it into a new bezel.

The portion of the top of the bezel holding the stone is wavy and irregular

If the top of the bezel and the stone are not in full contact, the top must be burnished to gain full contact.


The top of the bezel is unfinished, irregular or thin

The top of the bezel should be of even thickness and finished (perhaps bright cut).

Stone set too low

The table of a bezel-set stone should be slightly above the folded or burnished edge of the top of the bezel. This one is set too low, an error in workmanship.

illustrations by Lainie Mann

 

©1998 Jewelers of America
Standards as described by the JA® Bench Jewelers Certification Program



Copyright © 1998 by Bond Communications.


 

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