Gem FAQS > Gemstone & Jewelry News & Updates > July 2010- Lead Glass Filled Ruby

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This 6 ct lead-glass-filled ruby appears to have been damaged by immersion in jeweler’s pickling solution (top). A red substance present near the surface of the fractures may have been intended to disguise the damage (bottom). Photos by Shane F. McClure; bottom field of view approximately 1.25 mm.
Lead-Glass-Filled Ruby Damaged
During Jewelry Repair
Ruby filled with lead glass has been the source of much concern in the jewelry industry for several years. One of the main reasons is that the filler material is not durable -- tests have shown it to be highly susceptible to damage from solvents, even relatively mild ones like lemon juice. The initial GIA study of the durability of these stones found that jeweler’s pickling solution rapidly etched the lead glass filler at the surface.
In that article, we recommended that jewelers remove filled rubies from their settings before repair procedures to prevent damage. Unfortunately, jewelers sometimes don’t examine a stone thoroughly enough to identify a treatment, or they depend on what the client says. This practice often leads to problems during repair procedures.
One such case is illustrated at right. This 6 ct ruby was sent to the Carlsbad lab because it had been damaged during repair procedures and the jeweler wanted to know what happened. While the exact circumstances were not revealed to us, the stone’s appearance suggested that it was left in the setting during soldering or retipping, then placed in a pickling solution for cleaning. This is standard procedure and will not usually harm a ruby.
As we reported earlier, however, rubies filled with lead glass are certain to be damaged, causing a significant change in the stone’s appearance and a very unhappy client. To the best of our knowledge, these stones cannot be retreated once they are damaged; in this case, it appears someone tried to hide the damage by applying a red substance (possibly ink) to the surface, hoping it would penetrate into the fractures and make them less visible. If that was the intent, it did not succeed.
- Shane F. McClure
GIA Laboratory, Carlsbad

Last updated on January 16, 2012 by Francis M Lynch