Hello,
It appears that our current favourite diamond simulant shares
with Sapphire the affinity for borax glass and subsequent
destruction of the polish during prong retipping with the stone
in place. Perhaps another reason to always remove a stone before
soldering or at least establish exactly what you are working
with. This job came to me by way of a local diamond cutter. The
job bag shows the retipping job came in as a diamond
ring…woops.
An interesting observation was the way much of the flux was
burnt leaving tiny black specks on the damaged surface. After
repolishing the crown the pavilion specks reflected around inside
the stone like tiny carbon inclusions. My thought at this point
was how suspicous is one likely to be when confronted with an off
colour included diamond at a bargain price?
I noticed that this stone had a thick polished girdle and have
been assured that this is common practice, seems like a dead
giveaway to me. This would be an almost impossible or at least
incredibly arduous task to perform on a diamond. I put a highly
polished setters girdle (three-angled rounded) on the stone to
convince the next guy that he had a simulant.