Gem Labs Introduce New Ruby ID Nomenclature

By definition, red transparent corundum is ruby. But in some glass-filled specimens, the filling not only masks fractures but also acts as an adhesive to hold the stone together. Now the New York Gemstone Association is raising the alarm over disclosure.

NYGA president Benjamin Hakimi writes, “The board of directors of the New York Gemstone Association, representing 37 wholesale gemstone importers in the greater New York area, continues to be concerned about the lack of proper disclosure of ‘lead’-filled corundum.”

Hakimi and other members of NYGA have asked laboratory gemologists to consider clearer and more direct language to describe this material. The labs have changed their nomenclature, but discontent persists.

Until recently, most gem identification reports called such material ruby, and included the comments “glass-filled, with evidence of heat.” While gemologically correct, this language hides more than it reveals, says Jeffrey Bilgore, a colored-stone supplier and jewelry designer in New York. “I am tired of the subtleties of high gemology,” Bilgore says. “Someone needs to tell it like it is.”

Three of the major colored-stone gem identification labs—the Gemological Institute of America, American Gem Trade Association, and American Gemological Laboratories—have introduced new identification conclusions or are working on it. But the trade is awash in thousands of carats of glass-filled material, some of which has been identified by laboratories as ruby. This may be part of the dilemma facing labs as they struggle to find the right words to describe the material.

AGL has the strongest language:

  • Identification: Composite ruby

  • Standard Enhancement: Heat

  • Additional Enhancement: Lead-Glass

  • Comments: This ruby has been heavily treated using a high-refractive-index lead glass to fill fractures and cavities, vastly improving the apparent clarity and potentially adding weight. The glass may be damaged by a variety of solvents.

  • Stability: Good to Fair

AGTA’s Gem Testing Center also has changed its reports, using the standardized language and criteria set forth by the Laboratory Manual Harmonization Committee, which reads:

  • Species: Natural Corundum

  • Variety: Ruby

  • Enhancement: Indications of heating, TE; significant clarity modification, F3, C21

  • Comments: Lead glass has been identified as the filler. Lead glass filler may be unstable to elevated temperatures and to chemical agents. Special care shall be taken when repairing jewelry items set with lead glass–filled corundum.

GIA Laboratory reports are gemologically correct, but do not address the nomenclature problem:

  • Species: Corundum

  • Variety: Ruby

  • Treatment: Indications of heating and (significant) clarity enhancement using a glasslike compound to reduce the visibility of fractures.

  • Comments: [Lead] glass filler may be unstable to elevated temperatures and to chemical agents. Special care should be taken when repairing jewelry items set with glass-filled corundum.

GIA is still holding meetings to discuss possible changes in the wording.

Bilgore isn’t mollified: “This is way too little and way too late,” he says. Bilgore believes the labs should have recognized the problem immediately, and he says stronger wording should be used. “These are not gemstones. They are created products, and the labs should have seen it and called it what it was long ago.”

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