GTL Calls Suspect Blue Sapphires ‘Heat Treated’

After a year of extensive research, GIA's Gem Trade Laboratory (GTL) has concluded that the color variation observed in a number of heat-treated blue sapphires is simply a product of the specific heating regimen used by one Sri Lankan lab operator, Punsiri Tennakoon. A GTL press release dated April 14 states, "We have found no evidence of intentional or inadvertent diffusion of elements from an outside source that would require special disclosure on our gemstone reports." These gems will be disclosed with GTL's standard "heat-treated" comment, which will read as follows on a GIA GTL identification report: "NATURAL SAPPHIRE, [weight]. Comments: Evidence of heat treatment is present." Suspect sapphires. Early in 2003, GTL, AGTA's Gem Testing Center laboratory, and the SSEF laboratory in Basel, Switzerland, all noticed unusual color concentrations in a number of heat-treated blue sapphi

This content is exclusive to JCK Pro subscribers. Subscribe now to access this and much more with discount code GOPRO21 for $199 for an entire year of access (reg. $249).


Already a JCK Pro? Log in

A JCK Pro subscription is your all-access pass to people and resources on the
cutting edge of the retail jewelry industry, from the industry authority you
know and trust

Learn about the Perks of JCK Pro

Log Out

Are you sure you want to log out?

CancelLog out