Professional Jeweler Archive: Taking the Heat

July 2000


Taking the Heat

New filler aims to solve the problem of heat-sensitive clarity enhancements

Oved Diamond Corp. has developed a diamond clarity enhancement designed to withstand temperatures created by a jeweler’s torch during mounting and repair operations. Until now, fracture-filled enhancements have had limited applications because they could melt under a jeweler’s torch and exit the diamond. (Normally, torch temperatures reach 1,200° F.)

Oved Diamond, New York City, is test-marketing the product with five retailers across the U.S. and is conducting formal marketing and consumer research to determine the best approach.

“This new development means we are increasing the capacity for a volume market,” says President Jonathan Oved. “Jobs that were not possible before, such as bezel settings that require heat from a jeweler’s torch, can now be used in designs featuring our diamonds.” Oved says his company clarity enhances diamonds that are 0.2 carat and larger.

The Product

The proprietary filler, called XL-21, was developed by a chemical engineer. Oved says its ability to permeate surface-reaching fissures depends largely on the nature of the imperfection. The company has been successful with about 75% of the diamonds it treats. XL-21 reportedly has a similar refractive index to diamond’s, which renders treated minute surface-reaching fissures and fractures much less visible. While XL-21 reportedly is stable to sunlight and can withstand ultrasonic cleaning, the company says it’s soluble in strong acids.

At press time, independent tests of XL-21 were being conducted at the Gemological Institute of America’s Gem Trade Laboratory in New York City. Tom Moses of the GIA lab says preliminary tests on a few of the clarity-enhanced diamonds indicate the filler appears to be stable when subjected to normal bench jewelry work, including prong retipping and steam and ultrasonic cleaning. Moses cautions additional testing needs to be done, including solar simulation, higher temperature testing and a larger selection of diamonds.

The Brand and Disclosure

A bezel facet on each diamond’s crown carries the Oved logo. While most branded diamonds are laser-inscribed along the girdle, Oved officials say girdle inscriptions can be deceiving – they can be hidden in the setting of a mounted diamond. If girdle inscriptions are not easily discernible, it’s possible proper disclosure of the enhancement may be overlooked, confusing or deceiving consumers.

Oved’s logo is distinctly visible with a 10X loupe. Oved says the inscription on the bezel serves as identification and a disclosure tool, as well as a way to tout the company name. The company is negotiating with gemological laboratories to obtain independent certificates for the enhanced diamonds.

Oved’s enhancement isn’t the first heat-resistant filler developed, though it is first to the market. Yehuda Diamond Co., New York City, says it previously invented a heat-resistant filler but never marketed it. The filler’s refractive index was too different from diamond’s to adequately mask the fissures, says President Dror Yehuda.

GIA’s Tom Moses says he received some of these diamonds from Yehuda Diamond Co. but has not tested them. “What I find encouraging is that Oved has committed such an investment to researching this area,” says Moses. “It is a worthwhile pursuit because a successful product would remove one of the last remaining obstacles or concerns that someone could have in handling these stones.”

Promotions and Updates

Oved-branded diamonds were scheduled to be promoted heavily in consumer bridal publications such as Modern Bride beginning last month.

Enhancement with older, non-heat-resistant substances will be phased out as the success ratio with XL-21 increases, says Oved. Prices for the new clarity enhancement service will be the same as for the older enhancement. Oved customers with diamonds bearing the old enhancement can return them for re-enhancement. “While we will have to do it gradually,” Jonathan Oved says, “the re-enhancement service will be free.”

Further announcements to the trade were scheduled at the JCK International Jewelry Show in Las Vegas in June and via an educational Web site still in the works.

  • Oved Diamond Co., New York City; (212) 302-0047.

– by Robert Weldon, G.G.

Detection of Oved’s XL-21 filler is similar to that of any fissure-filled diamond. Under magnification, with darkfield illumination, the interface between the fissure and the filler can sometimes be observed in the form of a broad, bluish-purple or orange flash. The diamond may have to be rocked back and forth to capture this effect. Diamond is courtesy of Oved Diamond Co., New York City.
Oved Diamond Co. hopes to reach a much broader market with its new heat-resistant clarity enhancement. Oved says the new filler, called XL-21, remains stable under temperatures typically created by a jeweler’s torch. Diamond is courtesy of Oved Diamond Co., New York City. Oved’s clarity-enhanced diamonds are branded with a laser inscription on a bezel facet. The logo, which can be seen clearly at 10X magnification, serves as automatic disclosure of the enhancement. The logo is here seen at 45X. Diamond is courtesy of Oved Diamond Co., New York City.

Copyright © 2001 by Bond Communications