No stone left unturned

Tens of thousands of gems are inspected and certified annually by GCAL in a meticulous process that may soon bring profound change to the famously secretive diamond industry, which has long been averse to any measures that would give greater transparency to its dealings or allow auditing of the trade. Diamond dealers around the world have always operated on trust and a handshake, but that is no longer good enough in a world where diamonds are sometimes traded to pay for civil wars and terrorism.

Diamond wholesalers have an agreement among about 90 countries that effectively ensures that rough diamonds come from only legitimate sources. But not much has been done to reassure buyers of cut diamonds at the retail level. That is where GCAL hopes to build its business, by issuing certificates that follow individual diamonds, from the time a rough stone is cut into a jewel through every subsequent sale, thus guaranteeing buyers they are getting 8216;8216;clean8217;8217; diamonds.

Although there is practically no way to test a stone retroactively to determine its origin, certificates like those from GCAL offer a guarantee for any recently mined stone that conforms to this worldwide agreement, called the Kimberley Process.

One of the features making GCAL certificates effective is the use of a device called Gemprint, which, by shining a laser through a diamond, captures its unique sparkle pattern, just like a human fingerprint. A copy of this Gemprint image goes on each GCAL certificate, making it impossible to switch stones or claim a stone is better than it really is. The guarantee can only be thwarted by completely recutting a diamond, at a considerable loss in size and value.

An Israeli company originally developed the Gemprint technology 25 years ago, but it is only now coming into commercial use, partly because of resistance from the diamond trade and partly because 8216;8216;nobody could figure out what to do with it profitably8217;8217;, said Michael M. Haynes, the chief executive of Collectors Universe, firm that acquired GCAL and Gemprint late last year.

Palmieri, 59, a former diamond miner who is widely regarded as a gems expert, said Gemprint certificates had been accepted in law enforcement and the insurance business, because they aided in identifying stolen jewellery. Getting the diamond trade to participate took longer, Palmieri said, because obtaining a certificate for every single cut stone obliges diamond dealers to provide an audit trail for the rough stones they handle. This is something that dealers have resisted in the past, he said.

GCAL keeps a database of every stone it certifies, which now includes half a million cut diamonds. Palmieri expects to be adding that many more per year within a few years. Once GCAL has certified a diamond, company experts use a cold laser to engrave a logo and serial number onto its rim, though Palmieri admits that such markings, only a few microns deep, could be easily removed. It remains to be seen whether and how fast GCAL8217;s certificates catch on in the retail diamond trade. It may be some time before there really are no more secrets, bloody or otherwise, on 47th Street.

8212;MATTHEW HEALEY