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What turns diamonds yellow?


#1

What turns diamonds yellow? I have a diamond that was white and now
looks kind of yellowish sometimes. I know that there are yellow
diamonds and this one wasn’t a true white diamond. Just wondering. .
. Thanks for any info you can give me.

Donna


#2

Donna, Diamonds in nature, at least those in the yellow to white
range of color, almost always have a bit of nitrogen trapped in the
crystal structure. That’s what gives them their yellow color. Note
that this isn’t something that changes under normal conditions.
White or near white stones simply don’t become more yellow with
time. Doesn’t happen.

If your diamond now appears more yellow than it used to, there are
several possibilities. The most likely is that there is some dirt or
something of the sort coating the stone, perhaps only in a small
area, which is causing the appearance of a shift in color. A good
cleaning, perhaps using professional equipment such as an ultrasonic
cleaner (not the cheap consumer level “sonic” cleaners. Ultrasonic
cleaners are quite different, and much more costly. AND much more
effective) and steam cleaners might be needed to get off some
stubborn deposits, especially if they’re trapped between the stone
and it’s setting.

Another possibility is that the stone is the same color it’s been,
but wear and tear on the mounting, changing the appearance of the
mounting, may affect how the color of the stone now appears. For
example, if the mounting has yellow gold on it, which was highly
polished, but now is not, the more visible yellow color of the gold
may fool the eye in thinking the diamond is also more yellow. Some
gold mountings, even yellow gold, may be initially plated in parts,
with rhodium, a very white metal. If that wears off, what then
remains to reflect light into or around the stone, may be yellower,
again changing your perception of the stone’s color.

Another, but quite unlikely possibility, is that the stone is it’s
same color now, but that now you see the color, whereas when it was
new, it may have been masked. Some few unscrupulous sellers have, now
and then, altered the appearance of faintly yellow diamonds by
painting on, usually as a thin line just under the girdle of the
stone, on the back, a transparent but very lightly blue dye.
Normally it’s not easy to see, but it does reflect bluer light into
the stone, causing the stones apparent color to be whiter. This
coating isn’t permanent, usually, especially under the attack of the
aformentioned professional level cleaning equipment, so a good
cleaning by some other jeweler might remove that coating, leaving
your stone looking as it really is. Please note that this practice
is very uncommon today, so this is kind of far fetched as a
possibility. Still, it’s there, and every so often one hears of
someone trying to do this still.

Light sources in your home can also make a difference. Some lights,
especially fluorescents, dont’ show yellows very well, while others,
incandescents, increase the yellowish appearance of things. If
you’ve changed the way you light your environment, the apparent color
of your diamond may have followed suit.

With all that said, again the most likely explanation is just that
your diamond needs a good professional level cleaning.

Hope that helps.
Peter Rowe


#3

You ask: “What turns diamonds yellow?” Answer: Nothing. (with the
possible exception of radiation.) It is possible that the diamond
was “off-color” (yellow-ish) and the color was being masked by the
way it was set. It isn’t common, but unscrupulous dealers have been
known to ‘paint’ diamond girdles to improve the apparent color. It may
have gotten dirty recently, in a way that would make it appear that
the color had changed. But I believe it is very likely that the
inherent color has not changed. I will be interested in the opinions
of other Orchidians. David Barzilay, Lord of the Rings


#4

Donna, the yellow color you see in diamonds is caused by Nitrogen
atoms replacing carbon atoms within the crystal lattice or crystal
structure of the diamond. Nitrogen is the impurity, and the more
Nitrogen atoms present, the more intense is the yellow. If I
understand your question correctly, you believe that the yellow
color in your diamond has become more intense over time. I have
never heard of this happening, nor do I believe this is possible
without special treatment. Maybe you are looking at your diamond
under different lighting conditions, such as incandescent lighting
instead of natural. Charles Heick Cincinnati, Ohio


#5
 You ask: "What turns diamonds yellow?" Answer: > Nothing. (with
the possible exception of radiation.) 

Well I can’t resist telling a story here. I once knew a woman who
routinely got bored with her diamond engagement ring. So she’d take a
highlighter and color the diamond. For a few days it would be yellow.
Then she’d toss it into the ultrasonic to clean it off. Then it would
be green for a few days, then blue, then pink… Ah, the endless ingenuity
of human beings.


#6

Dear Donna, Over the years, I occasionally run into a customer’s
diamond that has picked up a yellow color, and after asking
questions, have come to the opinion that the problem may come from
their water source. Often they have well water that is very “hard”,
and high in mineral content, and it results in a build-up on and
under the diamond. Try a bath of warm pickel overnight, or if that
is not enough, you may have to go to sulfuric acid to remove the
deposits.

Good luck,
Jon