Opal & Diamond Pendant
Bezel Setting an Opal
1. Of all the stones in the world, opal is my favorite. I was especially excited when this 13.76 carat heart shaped opal was given to me to be set. The white gold mounting was made by a friend who doesn’t have much experience bezel setting fragile gemstones. My friend asked if I would help him out and set the stone. I think it’s good for bench jewelers to work together. We cannot be expert in every area and by seeking help from others, we can learn from their experience and improve our skills.
2. The model for the frame had been made using the Matrix computer program and then cut on a Revo mill. These systems do save a lot of time, but they cannot match the detail achieved from hand fabricating a piece. The mounting’s white gold bezel is too thick to safely set the opal, so I decided to add a yellow bezel to the mounting. The softer yellow gold will make setting the opal much easier. In the picture I am cutting a length of 1/2 mm thick bezel strip. I always find that fabricated bezels are much more uniform and predictable to work with than cast ones.
3. After cutting, my length of bezel strip was annealed to make sure the metal was “dead soft”. Bending the bezel strip to contour tightly around the opal is tedious work and it has to be done very carefully. The number one trick to bezel setting is a tight fitting bezel. If I leave any gaps between the bezel and the stone then the metal will need to be pushed that much further during setting. The metal can only be moved about a ½ mm before it will become work hardened and that would make this setting job more dangerous.
4. Once I’m satisfied with the fit, the bezel strip is marked and cut to the proper length. It would be better to err on the side of too tight than too loose. If the opal will not fit then I can always lightly hammer the bezel to stretch it if necessary.
5. The two ends of the bezel are then soldered together. It is my preference to use the best quality solder that I can purchase. I never use repair or other low temperature solders. Cheap solders often do not contain even 10K gold and these solders will readily pit when heated and in time they may tarnish. I do not know any bench jeweler who makes high quality jewelry using low quality products.
6. Once the bezel has been soldered and fitted to the stone it is time to make a support ring to fit inside. This ring will serve as a rest that will keep the opal at the correct depth in the bezel.
7. The support ring should fit snuggly into the bezel so there is no need for binding wire to hold it during soldering. A very wise man named Jose’ Godoy taught me to solder. One of his tricks was to use very finely ground boric acid powder mixed with alcohol as a de-oxidizer prior to applying flux. I have seen many bench jewelers using coarse ground boric acid crystals which can actually inhibit the flow of solder. Jose’ would always grind his own boric acid using a mortar and pestle to insure it was as fine as possible. As a reminder, both the deoxidizer and the flux will only work for approximately one minute. After that you should stop soldering, clean the piece and reapply a fresh coating before continuing to solder. Also there should be no gaps between metal components that solder would need to fill.
Opal & Diamond Pendant continued