Question
18ct White Gold Diamon
Hello Thomas,
thank you very much for your time.
I have this vintage white gold brooch that is set with sapphires and omc diamonds. When I bought it a few years back it already had an area that was tarnished (blackish). This tarnish is now spreading. I am surprised that it can tarnish at all. I have a valuation for it that states 18ct white gold. It doesn't have a hallmark. Ordinary cleaning lotions don't remove this. How can it tarnish at all and how can I clean it?
Thanks you.
Kind Regards,
Ines
AnswerInes, thanks for the question. I have unfortunately been delayed a day due to a problem with my computer firewall. Now, I am up and running again. : )
Thanks for the fine photograph. I see the tarnish very easily. I have seen white gold tarnish like this but not often at all. White gold was not introduced to the public until sometime in the early 1920's, being formulated in 1912 in Germany, I think. Prior to that, silver and platinum were the white metals for jewelry. I would want it reconfirmed that the lower section of the beautiful brooch is 18k gold, this being because the tarnish does look like that seen on silver. However, the bow appears to have no tarnish. Is that correct?
Likely this is 18k according to the valuation you have for the brooch. I would get the tarnish removed by a jeweler. The jeweler will use a soft buffing wheel and the tarnish will be gone and all will look quite nice again.
Home remedies are not the best for this sort of tarnish. However, you can try rubbing the metal with a wet paste of baking soda using your fingers. If the tarnish is removed, the surface will look clean but not be so shiny as would result from a jeweler doing the light buffing.
Please check where the brooch is stored. You do not want any rubber products, chemical household fumes and even unknown fumes released from old wooden boxes, etc. to reach the brooch. I suggest if the tarnish continues, keep the brooch stored in a zip-lock style baggie to keep the air off.
Why the tarnish? That is an unknown. With an old item, we really do not know the mix used in the white gold alloy. Perhaps that is more susceptible to tarnish than modern mixes. That is uncertain. Almost always it begins with some environmental contact.
Ines, I realize the mystery is not truly solved. Yet, I do hope this answer will assist in some way.
God Bless and Peace. Thomas.
