Christie's, New York, April 2010

Lot 163 A Sapphire and Diamond Ring, By Fred Leighton

Set with a cushion-cut sapphire, weighing approximately 6.02 carats, flanked on either side by a half-moon diamond, to the circular-cut diamond gallery and hoop, mounted in platinum, ring size 5¾
Signed Fred Leighton, with maker's mark for Tanagro

With report GRS2001-07187 dated 27 July 2001 from the GRS GemResearch SwissLab stating that gemmological testing revealed characteristics corresponding to those of a natural sapphire from Burma (Myanmar). No indication of thermal treatment