Re-tipping with chipped diamond

Dear Bench Jewelers/gem experts, A ring came in for retipping on 3 of
4 tips and tip replacement on the forth prong. The diamond had a
huge chip where the one tip used to be and numerous chips all around
the diamond. It was the customers grandmothers ring. I told the
lady that I do the work for that she needs to show it to her
customer and let her know about the chips before I do any work on
it. My instinct is that the diamond may crack from the torch when I
re-tip, is this a possibility or not?

Thanks, Marta

Yes it is a risk when a diamond is already chipped that cracks may
extend when you retip a prong. It might be better to suggest that
the stone be removed for the work and all the prongs be redone at the
same time (at a higher charge of course).

Daniel R. Spirer, GG
Spirer Somes Jewelers
1794 Massachusetts Ave
Cambridge, MA 02140
617-491-6000
@spirersomes
www.spirersomes.com

Most likely the chips on the diamond where made from the stone being
hit over the years and probably would not get worse from retipping.
BUT you always need to be careful and warn the customer. You did not
say what size the diamond is, but when all the prongs need work I
suggest replacing the whole setting. It is usually not that much
more money and you get a much nicer job in the end.

Bill Wismar

It is ALWAYS possible (but not likely) to crack a diamond when
heating with a torch. I’m sure you know that you should not quench
rapidly. However, my first concern, is that if this stone has
"numerous" chips, that it may not be a diamond! You should be
certain that is is, and that owner of stone knows the risk, before
using a torch on it. Always good advice: C.Y.A. (cover your tuchus.)
David Barzilay, Lord of the Rings

Hi Marta;

I don’t think there’s that great a risk to heating the stone. Heat
slowly at first, then after you’ve done the re-tipping, place the
ring on a charcoal block you’ve heated with your torch so that it
cools slowly. Diamonds are pretty tough. Others may disagree. You
can always avoid the risk by removing the stone and replacing the
prongs and re-setting. That entails a certain risk too of further
chipping. If it was mine, I’d re-tip on the stone.

David L. Huffman

 However, my first concern, is that if this stone has "numerous"
chips, that it may not be a diamond! 

I regularly take in repair jobs with old, chipped diamonds.
Diamonds actually can break fairly easily and older stones are often
broken from banging against other diamonds or just simply rough wear
and tear. As it happens I looked at an old mine cut diamond today
that looked like someone had a taken a hammer and chisel to the
girdle.

Daniel R. Spirer, GG
Spirer Somes Jewelers
1794 Massachusetts Ave
Cambridge, MA 02140
617-491-6000
@spirersomes
www.spirersomes.com