Platinum and Diamond Ring, Harry Winston. Photo Sotheby's

Centering an emerald-cut diamond weighing 12.36 carats, flanked by two tapered baguette diamonds weighing approximately .50 carat, size 4½, signed Winston.With signed box and pouch. Estimate 300,000 — 400,000 USD

Accompanied by GIA report no. 14900981 stating that the diamond is H color, VS1 clarity.