National Jeweler Network


AGL calls attention to ‘composite’ change

September 09, 2013

This photo provided by American Gemological Laboratories shows a composite ruby that has been damaged during jewelry repair, which happens due to the high content of lead-glass in these stones.

New York--The American Gemological Laboratories (AGL) recently pointed out a “pivotal” change in disclosure nomenclature by CIBJO: the use of the word “composite” now can be used to describe lead-glass treated rubies, a change the AGL said many overlooked following CIBJO’s meeting in May.

Following its 2013 conference in Tel Aviv, CIBJO, the World Jewellery Confederation, issued a press release explaining that going forward, it would follow the Laboratory Manual Harmonization Committee (LMHC) disclosure guidelines for lead-glass treated rubies and recognize the use of the term to composite to describe the stones.

This is a change the AGL advocated for, but one that was largely overlooked in post-conference reports and not widely understood in the industry, the lab said.

“At the time of the press release, most publications focused primarily on the CIBJO decision to follow the LMHC in disclosing this product, without much mention of their pivotal change allowing for use of the term composite to also represent these stones,” the AGL said.

The previous definition of composite in the CIBJO Blue Book did not permit the word to be used as a description for lead-glass treated rubies.

“This was a significant ruling for the CIBJO colored stone committee to make, which required a revision of the by-laws of the definition for the term composite,” Smith said. “It was not unexpected that the CIBJO ruling would follow the terminology proposed by the LMHC. However, they also approved the use of the word composite for this product, which was pioneered by the AGL.”

Lead-glass treated rubies began entering the jewelry market in vast numbers in 2003.

The creation of these stones involves taking very low quality, industrial-grade ruby and infusing it with glass that has a high lead content. Some stones are more ruby than glass while other are more glass than ruby.

In either case, the AGL said the amount of glass in these stones is significant and they must be handled carefully because the glass can be damaged by a variety of standard practices used by bench jewelers and even household products such as cleaners.

The LMHC has a multi-tiered disclosure system in place for lead-glass treated material that is dependent on the level of treatment, but AGL collectively describes all of this material as composite.

Additional trade organizations that recognize the term composite for lead-glass treated rubies are the American Gem Trade Association, International Colored Gemstone Association, Gemstone Industry and Laboratory Committee and the Jewelers Vigilance Committee.