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Diamond discoloration

I recently soldered new posts on a pair of diamond earrings with the
stones in place and they turned quite yellow. What caused this and
how can the problem be corrected?

Your earrings may not have been absolutely clean before you soldered.
This is absolutely imperative or you will cook the grime onto your
diamonds and inside your settings.

We used to clean diamond set jewelry by boiling in lye, ultrasonic
cleaning and steaming to clean out accumulated grime whenever we had
to work on them with a torch.

Donna Shimazu

I recently soldered new posts on a pair of diamond earrings with the
stones in place and they turned quite yellow. What caused this and
how can the problem be corrected?

Here’s one possibility: If a diamond is dirty when it is subjected
to heat, the dirt can burn into the surface of the stone causing
permanent discoloration or black marks that look like inclusions. If
this is the cause, the only solution is to repolish the stones. When
soldering diamonds in place, always thoroughly clean them first and
then keep your hands off them: Diamonds are oil magnets.


There could be a couple of reasons for the discoloration: 1. you did
not thoroughlly clean the item before soldering, and the residue on
the back of the stone formed a crust. 2. You used too much flux and
it formed a crust on the back of the stone. If you had burnt the
diamond it would have turned milkey white, unfortunately I have
several, Simply pickle the items (the pickle should be on the strong
side and a very slow boil for up to a half hour) , then if you have
an untrasonic cleaner finish the cleaning with that… Naturally if
you have a steamer, then life will be easier.

The old saying that cleanliness is next to something or other, is


Most likely the reason the stones discolored is because you did not
clean them thoroughly enough before soldering the posts on. Diamonds
need to be absolutely spotless before soldering them. Of course you
might have also burned them. In the first case you need to use some
acid to clean them in. In the second case you need to have them recut.

Daniel R. Spirer, G.G.
Spirer Somes Jewelers

Hello, Your stones may be synthetic moissanite. When heated moissanite
change color and become yellow. But it turns to original color when
it cools down. Check looking from the table if the pavillon facet
edges look doubled. Diamond is isotropic. You will see only one line.
Kind regards from Turkey, Oya Borahan Please check
the “Woven Trabzon Bracelets” in my web site in"My country"
page. It may be interesting for some of you.

Oops, Sounds like you just had your first experience with fracture
filled diamonds. Not to fret too much, check with a certified
gemologist and if they are filled, inform your customer. Then, contact
one of the companies that fill diamonds, they have methods to remove
the old filler material and replace it with new( for a fee ). You
really shouldn’t be held responsible, but if the customer squawks,
offer to split the cost ( after all, disclosure works both ways)

Dean D. Amick

A couple of years ago, I was asked to set a diamond into a stock
piece for a client. Having done work for this client for a
considerable time, I didn’t take any real time to inspect the stone.
We have learned to trust each other in these matters. At some point I
heated the stone. It discolored pretty badly. When I took it to him,
he called his supplier. A much trusted supplier. None of us had
noticed that the stone was Yehuda treated. Laser drilled and filled.
Not a real big problem. The supplier took it back. Good
thing that it didn’t get out of the door with no one noticing.

Hello, If a diamonds turns yellow during a soldering process, it was
probably dirty. The yellow is just dirt burned onto the surface.
Pickling and cleaning should take care of it. If a diamond is
actually damaged from heat, it will acquire a whitish milky surface
that only a diamond cutter can remove. Tom Arnold

The yellow is just dirt burned onto the surface. Pickling and
cleaning should take care of it. 

I’ve also found that re-firecoating and re-heating until firecoat is
glassy then (when diamond is cool of course) re-pickling will also
help carry away any burnt on dirt. I repeat this if necessary. Its a
great and tedious learning experience for how important it is to get
things totally clean before heating!


To prevent diamond discoloration, which is really just grease or dirt
being burnt on the stone always ultrasonic the stone in the ring
first. Usually there is all sorts of crap up behind the stone from
soap to many years of dust. Now, if you need to then get the
discoloration off,(and its set in a ring) pickling and ultrasonic
won’t help because its burnt on, its easy to get off on the table of
the diamond because you can just buff it off but you need to get in
and scrape it with a steel tool, whatever fits on the back. Not an
enjoyable process. Hope this helps. PS always make sure the piece to be
worked on is immaculately clean before putting under the flame Ed
Dawson Maine Master Models making models for the trade

Normally you should not apply flux on the diamonds.After soldering
allow the earrings to cool down completely before putting in
pickling.Normally a diamond can he heated to white.