Lead Glass Fracture Filling in Ruby
In March of 2004 the GAAJ issued a Lab Alert which described rubies that were being treated by a lead glass fracture filling technique. This was followed in July of 2004 with news that stones treated in this manner had entered the US market and further described in Gems & Gemology in the fall of 2004. Over recent months the AGTA Gemological Testing Center has observed an increasing number of rubies treated in this manner and reports from ruby dealers now indicate that significant parcels of these stones are being sold in the US market.
It is important that those buying rubies make themselves aware of the presence of this material on the market. If a stone is suspected of being treated;
If either flattened bubbles or color ‘flashes’ are seen in the vicinity of fractures, it is likely that the stone has been treated by this new technique.
The majority of lead glass fracture filled rubies examined at the AGTA-GTC have been extensively treated (figure 2). Contact the AGTA-GTC for further information
AGTA Gemological Testing Center
18 East 48th Street, Suite 502
New York, NY 10017