A cushion-cut ruby and diamond ring of approx. 12.43 cts.

Lot 294. Set with a cushion-cut ruby, weighing approximately 12.43 carats, to the pavé-set diamond hoop, mounted in platinum and 18k gold, (illustrated unmounted) - Estimate: $800,000-1,200,000
With report ID 14115 dated 4 October 2007 from the American Gemological Laboratories stating that no gemological evidence of heat enhancement present. Clarity Enhancement: None
With report 0612020 dated 11 December 2006 from the Gübelin Gem Lab stating that there are no indications of heating. Accompanied by an appendix stating that this ruby possesses a saturated and homogeneous colour, combined with a high degree of transparency. In addition, this gemstone has been spared of thermal treatment. Such a combination of characteristics is rare in natural rubies of this size

Christie's. Magnificent Jewels. 11 December 2007. 20 Rockefeller Plaza, New York