Two coloured diamond and diamond rings. Photo Christie's Image Ltd 2015.

A 3.64 carats brilliant-cut fancy pink diamond and diamond ring. Estimate HK$7,800,000 – HK$10,000,000 ($1,000,000-1,250,000). Photo Christie's Image Ltd 2015.

Set with a brilliant-cut fancy pink diamond weighing 3.64 carats, within a brilliant-cut diamond surround, gallery and half-hoop, mounted in 18k white and rose gold, ring size 5¼

Accompanied by report no. 1162587333 dated 21 October 2014 from the Gemological Institute of America stating that the 3.64 carat diamond is fancy pink, natural colour, internally flawless clarity

A 4.23 carats oval-shaped fancy pink-purple diamond and diamond ring. Estimate HK$7,800,000 – HK$10,000,000 ($1,000,000-1,250,000). Photo Christie's Image Ltd 2015.

Set with an oval-shaped fancy pink-purple diamond weighing approximately 4.23 carats, within a brilliant-cut pink diamond surround extending to the gallery, joined to the brilliant-cut diamond hoop, mounted in platinum and 18k rose gold, ring size 6

Accompanied by report no. 15308718 dated 23 February 2015 from the Gemological Institute of America stating that the 4.23 carat diamond is fancy pink-purple, natural colour, SI1 clarity

Christie's. HONG KONG MAGNIFICENT JEWELS, 2 June 2015, Hong Kong