Recent incidents of synthetic diamonds found mixed in
parcels of natural diamonds raised industry concerns about the reliability of
synthetic detection. More than 600 synthetic diamonds in F to J color and
weighing 30, 40, 50, 60 points and even a few 70-point stones, were discovered
by International Gemological Institute (IGI) in batches of melee sent to them
for certification. An added concern was that the stones were beautifully
polished so as to more closely resemble natural diamonds. The resulting
publicity has led labs to reassure the public about their detection
capabilities and about the improbability of a synthetic product being
fraudulently labeled — and sold — as natural.
“We don’t see a lot of synthetics in our lab because people
know we don’t certify such stones and so they are probably more likely to
submit them to other labs,” said Annick Gijsemans, senior manager of the HRD
Diamond Lab. “We’re following International Diamond Council (IDC) rules, which
give labs the option of deciding on their own whether they will issue or not
issue synthetic certificates.
“Until now, our choice has been not to issue any but, in the
near future, most probably in the beginning of 2013, this is very likely to
change,” said Gijsemans. “We’re now considering certifying synthetics as
synthetics because it’s a very hot topic in the market and we want to protect
consumers on their purchases. We don’t want our clients to confuse synthetic
and natural diamonds. So far, it’s been very rare that stones entrusted to us
as natural diamonds turned out to be synthetic. The important point to
emphasize is that if a synthetic enters the lab, there’s a 100 percent chance
that we will discover it.”
One of the issues with synthetic diamond detection is that
diamantaires, by and large, are not equipped to detect synthetics in parcels on
their own. This is more of a problem with the smaller stones, since the bigger
ones are, most of the time, if not always, already certified. With the concern
expressed by the industry regarding the increased presence of synthetics in the
market, being able to use simple off-the-shelf tools to detect them would be a
great help for diamantaires.
“HRD Antwerp has no problem in identifying synthetics or
treated stones, but the issue is that the sector is asking for a method for
batch screening of parcels of smaller diamonds to detect potential synthetics
or treated stones, so those stones could then be sent to a specialized diamond
lab for examination,” said Yves Kerremans, head of the HRD Research Department
and of WTOCD, a Belgian scientific and technical research center for diamonds.
What the market needs is a new generation of machines that
could help screen parcels of smaller diamonds. Noting that his lab has already
developed screening tools and techniques that were made available to
the trade,
including D-Screen, a compact screening device for individual diamonds,
Kerremans conceded that “these were not designed to screen quantities of small
stones. At this stage, unfortunately, I can’t give
you a time schedule as to
the future availability of such a tool but I’m
pretty confident that we can
come up with something that will meet the industry needs.”
Herman Z. Brauner, honorific president of the IGI Lab,
elaborated.
“We currently have a system that enables us to screen smaller
stones in larger quantities. With that equipment, we can process and screen
hundreds of stones at a time for 1-pointers to 5-pointers in small brilliants.
But, basically, the smaller the stones, the more difficult it is.”
Having said that, Brauner said he doubts that the risk of
seeing more smaller synthetic stones in the market will increase significantly.
“In order to create CVD (chemical vapor deposition) synthetic diamonds, you
must first grow your crystal layers. Then you have to saw them into little
cubes that will only then be polished by real polishers into brilliants — and
the cost for that polishing is the same as for natural diamonds. Furthermore,
those stones must also undergo HPHT (high pressure-high temperature) treatment
to improve their color because CVD stones are basically brownish. The overall
yield is about 20 percent. All things considered, the production costs are so
high that it’s not realistic to sell synthetic at prices below 50 percent of
the value of the natural ones. So the cost structure is quite prohibitive.”
Article from the Rapaport Magazine - October 2012. To subscribe click here.