Exquisite Fancy Intense Blue Diamond, Pink Diamond and Diamond Ring. Photo Sotheby's

Centring on a modified heart brilliant-cut fancy intense blue diamond weighing 3.04 carats, to a stylised mount set with circular-cut pink diamonds and diamonds, mounted in platinum. Ring size: 5¾. Estimation: 16,000,000 - 20,000,000 HKD

Accompanied by GIA report numbered 1112515853, dated 20 June 2012, stating that the 3.04 carat diamond is natural, Fancy Intense Blue colour, VS1 clarity

 Fancy Vivid Yellow Diamond and Pink Diamond Ring. Photo Sotheby's

Centring on a square emerald-cut fancy vivid yellow diamond weighing 13.10 carats, framed by circular, oval and marquise-shaped pink diamonds together weighing approximately 1.80 carats, the mount and shoulders decorated with circular-cut diamonds, mounted in 18 karat white and pink gold. Ring size: 6¼. Estimation: 7,200,000 - 9,000,000 HKD

Accompanied by GIA report numbered 1132613478, dated 1 July 2011, stating that the 13.10 carat diamond is natural, Fancy Vivid Yellow colour, VVS1 clarity.

Sotheby's Hong Kong. Magnificent Jewels and Jadeite. 8 April 2013 www.sothebys.com