A magnificent 17.97 carats step-cut diamond and an extremely rare Kashmir sapphire ring will lead the final Bonhams New York Fine Jewelry sale of 2016 next month (6 December), Art Daily reports.

Jewelry from celebrated designers including Cartier, Van Cleef & Arpels and Tiffany will also feature in the sale, which will consist of 179 lots in total.

Gracing the catalog front cover is a truly exceptional 17.97 carats rectangular step-cut diamond solitaire ring. Estimated at U.S. $1,000,000-1,500,000, the diamond is D color, VS1 clarity, Type IIa.

Susan Abeles, Director of Jewelry, Bonhams US, says: “Type IIa diamonds are regarded as the most chemically pure given they often have exceptional optical transparency. This particular stone is simply stunning and is the ultimate diamond for anyone to own given its rarity and beauty.”

The second leading lot Bonhams will be offering is a Kashmir sapphire and diamond ring by Shreve & Co. Dating from the 1900s, the cushion mixed-cut sapphire, weighs 6.90 carats, and has no indication of heat or clarity enhancement. It is estimated at U.S. $70,000-90,000.

Susan Abeles, Director of Jewelry, Bonhams US, adds: “The sapphires hailing from Kashmir display a velvety quality and a rich blue tone unique to the region. They are among the most highly-prized gems for serious collectors and investors given their extreme rarity.”