When Lazare Kaplan and General Electric first announced the Pegasus process, the trade thought it might be years before scientists could detect whether the stones were treated.
But it took a lot less than that. Two De Beers scientists, writing in the Spring 2000 issue of Gems and Gemology, say they have come up with a way to detect a “vast majority” of the diamonds. However, for now, this method is currently not simple enough to be done by most jewelers, according to reports.
The GIA has also identified a new laser treatment that does not have the surface-reaching drill hole traditionally associated with laser drilling.
The GIA notes that, in traditional laser drilling, a hole drilled to a dark inclusion in the interior of the diamond serves as a channel for the strong acid used to remove or minimize the dark material.
But this new treatment uses laser-generated heat to expand the cleavages of the diamond so you can pour acid through them, thereby soaking out the black piques. Naturally, the piques have to be close to the surface for this to happen. The laser leaves evidence of one or more internal channels within the cleavage or adjacent to the inclusion, but there is no surface reaching drill hole, and the lasering is only on the surface.
In a way, this is better than traditional lasering, since it is does not leave a drill hole. We even question whether it should be called “laser drilling,” because there is no drill involved.
On the other hand, this treatment is worse in some ways because it leaves an open imperfection, which could eventually gather dust and other particles, and hurt its brilliance.