Platinum, sapphire and diamond ring, Tiffany & Co. Photo: Sotheby's.

Set with a cushion-cut sapphire weighing 18.99 carats, within a floral mounting decorated with round diamonds weighing .57 carat, size 7½, signed Tiffany & Co., numbered 21455766. Estimation 100,000 — 150,000 USD 

Accompanied by AGL report no. CS 56099 stating that the sapphire is of Madagascar origin, with indications of heating.

Sotheby's. Important Jewels? New York | 24 sept. 2013.  http://www.sothebys.com