What the GIA Study Overlooked

Your January issue deals with “Ideal” proportions of diamonds as researched by the Gemological Institute of America and others (“GIA to Ideal Cutters: Back to the 3-D Drawing Board,” p. 96). But that research has almost totally neglected the most obvious contribution to the beauty of a diamond – symmetry. In fact, that word appears only three times in your five-page report! For instance, each set of opposing bezel facets and corresponding pavilion mains of a round brilliant-cut 58-facet diamond must be perpendicular to an intersecting plane in order to return maximum light to the eye of the viewer. Not once, but eight times around!

And most important, if the opposing pavilion facets fail to perfectly “mirror” each other, light is lost and brilliance is diminished. GIA’s computer modeling assumes perfect symmetry and quite correctly shows that proportions other than “pure Tolkowsky” might result in a diamond of equal or greater beauty. However, without introducing asymmetrical variations, the findings lack validity. But then, few cutters seem to recognize the importance of symmetry – except for the “hearts-and-arrows” cutters who have demonstrated this principle far better than the scientists at GIA and elsewhere.

Charles L. Wells, Jr., G.G., CGA, Former Chairman, AGS Diamond Standards, Jacksonville, Fla.

Time for the Industry to Save Itself

After the Tucson shows, I visited stores in a few U.S. cities, all of which displayed membership logos in their windows from various trade associations. I didn’t identify myself as a gem dealer; I just asked the sales staff a few questions about their goods. The responses were virtually the same in each store, indicating that the staff had been specifically instructed on what to say. In a nutshell, this is what I was told:

Some of the material is “genuine lab-created” ruby and sapphire, which is “quite different from, and superior to, synthetic stones.” No one could explain the “difference,” but it was assumed by the staff that “synthetic” was color-enhanced or glass, not “genuine” ruby and sapphire.

Clearly, the sales associates in all of these stores were confused over the differences among imitation, synthetic, enhanced, heated/non-heated, and natural stones. No doubt they are passing this confusion on to the buying public, a situation that can result only in distrust and bad feelings and, eventually, decreased sales for all of us in the industry.

At a store of one of the industry’s most prestigious names, I was shown heat-treated corundum and was told by the staff that “our firm has strict standards, and natural rubies and sapphires simply do not meet the quality level we demand.” The inventory of my own firm suggests otherwise.

It seems trade associations, as a major industry resource, should instruct and police their membership on how to market colored stone material. This point is not new, and disclosure in the gem trade is a matter of ongoing debate. But the obfuscation and confusion I witnessed go beyond mere disclosure and may well be considered deceptive.

If such practices were isolated, it would not be such a concern. But the fact that competing stores had sales staff who used the exact same wording suggests that it is standard practice.

Although my firm deals only in unheated, untreated stones and uses major industry gem laboratories to certify this fact, I appreciate that there’s room in the trade for all types of material, from imitation to synthetic, enhanced to natural. What has to be done – and there may be little time left – is that both training and disclosure have to be mandatory and consistent. If industry associations are to have any power, such rules must be mandated and enforced. If not, all of us in the trade, whatever our material, will suffer.

Andrew McGrath, Burma Partners, www.burmarubies.com

Ion-Beam Inscriptions

We’d like to further clarify the mystery surrounding the unique technique that was perhaps used by De Beers to generate branded diamonds (JCK, “Unmasking the Marque of De Beers,” January 1999, p. 28).

At Norsam Technologies’ R&D Lab in Oregon, we have demonstrated similar results with our focused ion-beam workstation. With this machine, we can precisely direct a beam of gallium ions onto a diamond substrate. The high-energy exposure converts the very dense crystalline structure of diamond to a less-dense form of ordinary carbon (graphite). As the density factor decreases, the resulting phenomenon is an increase in volume. This creates a bulging effect of “raised lettering” at the surface of the gemstone in the vicinity of narrow impact by the high-energy ions.

This is not a laser technique. And no chemical elements (except carbon, as mentioned in your article) are deposited. In fact, our focused ion-beam workstation can do much smaller inscriptions than any laser technique. We can easily print logos (three-dimensional), line drawings, unique typography, and special “millennium messages” at the sub-micron level (far less than the width of a hair), requiring the use of a high-powered magnifier to verify authenticity. This is also a highly automated process. With sophisticated software and by using a client’s computerized design profile, we can inscribe any brand or message on the table edge or girdle of a diamond or other precious gemstone.

Jayant Neogi, Ph.D., and Garry Nevins, Norsam Technologies, gnevins@ptld.uswest.net, www.norsam.com


An incorrect listing was given in the 1999 Jewelers’ Directory for Abbey Crest, Providence, R.I. To reach the Abbey Crest office in Providence, call (401) 724-9900.

C.K. Gumpert should have been credited as the manufacturer of the pearl and diamond star earrings in the illustration accompanying the article “Will Jewelry Sales Sparkle in ’99?” in the January 1999 issue of JCK (p. 118).

An incorrect address was given for The Sultan Co. on p. 254 of the January 1999 issue of JCK. The correct address is 3049 Ualena St., 14th Floor, Honolulu, HI 96819-1942.

JCK welcomes letters. Please include your name, address, and telephone number. Letters may be edited for clarity and length. Jeweler’s Circular Keystone, 201 King of Prussia Rd., Radnor, PA 19089.