Lot 265. Important Pair of 17.87 and 15.24 carats Burmese Cushion-Shaped Sapphire and 2.51 and 2.50 carats Old Mine-cut Diamond Pendent Earrings. Estimate：HK$ 9,500,000 - 12,000,000 (US$ 1,220,000 - 1,540,000). Courtesy Tiancheng International.

Each suspending a cushion-shaped sapphire weighing 17.87 and 15.24 carats respectively, surmounted by an old mine-cut diamond weighing 2.51 and 2.50 carats respectively, mounted in platinum and 18 karat white gold. 

Gübelin reports numbered 16010081 and 16010082, dated 21 January 2016, stating that the 15.24 and 17.87 carat sapphires are natural, Blue colour, of Burmese origin, with no indications of heating; both along with information sheets, stating that 'The demand for natural, unheated sapphires keeps growing while the supply of such gems remains limited, making large, natural sapphires of gem-quality from all major sources (such as Kashmir, Burma (Myanmar), Sri Lanka, Madagascar and Tanzania) difficult to find.'; and gemmological profiles, stating that 'With a final weight of 17.87 / 15.24 ct, the sapphire presented here is an extremely large specimen...Large, unheated specimens of sapphire displaying a saturated, equally distributed blue colour, such as shown in this 17.87 / 15.24 ct sapphire, are considered rare...The colour of the present gem is very pleasant, characterised by an intense, saturated and homogeneous blue colour, free of any overtone...The 17.87 / 15.24 ct sapphire described...is of very high visual quality. Only a small share of the sapphires coming out of a mine is of this level of quality, and hence considered rare.';

SSEF report and Premium Book numbered 83537, dated 12 January 2016, stating that the 17.876 and 15.249 carat sapphires are natural, Blue colour of strong saturation, of Burmese origin, with no indications of heating; along with comments, stating that 'The colour of the17.876 carat sapphire may also be called 'Royal Blue' based on SSEF reference standards.'; along with an appendix, stating that 'The pair of natural sapphires described...possesses extraordinary characteristics and merits special mention and appreciation. The described sapphires...have been carefully selected and precisely cut to form a highly matching pair in size and quality. Both sapphire exhibit an attractive and saturated blue colour combined with a fine purity. Their colour is further pronounced by its well-proportioned cutting style, resulting in vivid blue hues due to multiple internal reflections...The small inclusions found by microscopic examination are consistent with those found in sapphires from Burma (Myanmar). Their saturated blue colour - for sapphire A (the 17.876 ct) peotically also described as 'Royal Blue' - is due to a combination of well-balanced trace elements in these gemstones, typical and characteristic for the finest sapphires from Mogok, Burma. In addition to these quality, these sapphires have been spared exposure to heat treatment and their clarity and colour are thus all natural. Assembling a pair of natural sapphires from Burma of this size and quality is very rare and exceptional.'; 

GIA reports numbered 5131938969 and 2135557049, dated 11 October and 7 July 2011, stating that the 2.51 and 2.50 carat diamonds are G colour, VS1 and VVS2 clarity respectively.