A Burma sapphire and diamond necklace. Estimate HK$2,400,000 – HK$3,500,000 (US$300,000-440,000). Photo Christie's Image Ltd 2015

Designed as a series of graduated cushion and oval-shaped sapphires alternating with trefoil pear-shaped diamond links, mounted in 18k white gold, 42.3 cm long

Accompanied by report no. 76386 dated 23 September 2014 from the SSEF Swiss Gemmological Institute stating that the sapphires weighing approximately 70.00 carats total are of Burma (Myanmar) origin, with no indications of heating and the colour of part of these sapphires may also be called 'royal blue' in the trade

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