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Jewelry, Gems, & Minerals/Color Change of Stone After Heating


QUESTION: I have a sliced sapphire necklace - Ruby, Sapphire, Emeralds that a jeweler needed to reset, because the setting was weak. When I received it back, I noticed that the color of the stones was changed. The emeralds were the worst, they faded and became brownish near the setting where the soldering was done. The smaller emeralds lost more color than the larger ones.  The sapphires faded and ended up going from a bright dark blue to denim color. Again, the larger ones faired better than the smaller. The change in the smaller rubies was only slight. I am assuming that this is because of heat damage because the stone wasn't properly handled with respect to the heat. Could this be the case?
Thanks for your answer.

ANSWER: Lauren,

I would have to see the gems in my presence to be absolutely certain what you describe is heat damage. Yet, with that said, I do not know what else the cause could be.  Heat damage from soldering work does what you described and sometimes even worse.

The bottom line to it all is the stones are damaged and not like when you took the necklace for service.  If the jeweler could not do the work properly or did not know how, the job should have been refused. In any regard, I see the jewelers at fault here.

Best wishes in receiving a fair compensation or replacement for the damage.

God Bless and Peace.   Thomas.

---------- FOLLOW-UP ----------


QUESTION: You are correct Thomas, a picture would be helpful. Front and back images are attached. The necklace is flat and designed to have a front and back side. You can see from attached pictures how stones are no longer uniform in color as the stones change size, also you can notice brown marks near edges of some of the stones. So sad!

Dear Lauren,

Eveb with your fine photos it is difficult.  To have seen the stones prior to the work is not possible now. Yes, I do seen the discoloration at what would appear a soldering area on the bezel.  You are fortunate the emeralds are not totally destroyed. Heat is notorious for damage to emeralds.  Do those gems show more fractures internally than prior to the work?

I would have expected more damage to the emeralds, as I said above and so I wonder what sort of soldering was done. Was a lower temperature "soft solder" used? Those solders are not precious metal such as silver but more like used for electrical connections. Melting temperature is much lower( perhaps 400f) than with silver solders which flow at above 1100f.

A method for securing stones in these types of bezels is using epoxy cement to a slightly warmed stone and setting. A small item like a toothpick is used to touch the freshly mixed cement to the contact area of stone and metal. The warmth makes the epoxy very fluid and it will run into the area between stone and metal when applied right at that area. Very little is needed and with the cement used judiciously, it is not visible when cured and all is tight.  This is a thought should more service be needed.

Obviously the stones appear damaged and from the photos there is apparent discoloration. I cannot tell if the heat caused internal fractures. A light shown through the stone will reveal what is happening inside.

Best wishes. Yes, this is sad. Thanks for getting back with me. God Bless.  Thomas.  

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Have a question about jewelry repair or working with precious metal jewelry and gemstones? For many years up to December 31, 2010, I was a working professional bench jeweler, involved everyday with setting stones in mountings, designing and making jewelry, repairing and limited custom manufacture. If you work with jewelry as a hobby or as a profession, I might be able to help. I deal with the retail business, not mass production. Ask privately if you wish. See the box for that: It keeps your question between us. Please DO NOT ask MAKER'S MARKS, but metal quality marks are fine to ask. Please DO NOT ask diamond prices. See a gemologist for that.


I have extensive experience in design, service and making of jewelry. I deal mostly with precious metals and gemstones but work with many materials as needed and usable to create an artistic design. My experience also includes freelance photography and photographer of jewelry and similar items for a former employer and individuals. Design of custom items requires reading the desires of the client and being clear on what can be done within that framework...then fulfilling the transition of idea to reality. Effective communications is essential in a working designer/producer and customer relationship.

Education is English/Physics! Started in human resources, to advertising, to, what a road. I have had formal training in jewelry work and many shared experiences with top grade jewelers. We just never know were we will go or be. Follow your best, your dreams, with some discretion! Don't let the work tear up your body along the way as it has mine.

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