Impressive and Rare Sapphire and Diamond Necklace. Photo Sotheby's

Suspending a cushion-shaped sapphire weighing 102.61 carats, surrounded by brilliant-cut diamonds, completed by a double-strand necklace set with brilliant-cut diamonds, the diamonds together weighing approximately 60.00 carats, mounted in 18 karat white gold, length approximately 460mm. Estimate – $2,836,680 - $3,868,200 USD

Accompanied by AGL and SSEF reports numbered CS 58713 and 72488, dated 14 January and 5 February 2014, stating that the sapphire is natural, of Sri Lankan (Ceylon) origin, with no indications of heating. SSEF states that the colour of this sapphire may also be called royal blue in the trade; further accompanied by SSEF Appendix, stating that the sapphire “exhibits a highly impressive size and weight 102.614 ct, combined with an attractive blue colour and a fine purity.” AGL report also states that the sapphire ranked ‘exceptional’ in the Total Quality Integration Rating, for its “unusual combination of size, provenance, absence of treatment and quality factors present in this material contributes favorably to its rarity and desirability.”

Island of Azure Gems.
The unique quality that makes sapphires from Sri Lanka stand out is their exceptional clarity and luster, in combination with an excellent saturation of pure blue colour. Such fine specimens of charming blue gemstones were mined and traded as early as 500 BC and were greatly coveted by the Etruscans, Greeks and Romans. Sri Lanka is now generally considered to be the world’s first source of sapphires and many other gems; the abundance of fine sapphires in this part of the world was so remarkable that the Indians called Sri Lanka “Ratnadeepa”, which means “Island of Gems.” Some of the world’s greatest and largest sapphires come from Sri Lanka, including the renowned 422.99-carat Logan Sapphire and 98.60-carat Bismarck sapphire necklace by Cartier, that are both on display in Smithsonian Institution’s National Museum of Natural History.

The finest Sri Lankan sapphires exhibit a medium to bright blue colour, often lighter in tone as compared to Burmese sapphires, yet the colour distribution is surprisingly even despite their relative large sizes and heavy weights, this is due to tiny rutile needles, also known as ‘silk’, which is a common inclusion in sapphires that help to scatter light equally on its facets. Though similar to natural sapphires originating from other countries, inclusions are inevitable in even the finest sapphires in the world; Sri Lankan sapphires are highly prized for their high clarity, which allows maximum light return, resulting in an alluring lustre and lively brilliance that is rarely found in sapphires with intense deep colour. It is also rather common for Sri Lankan sapphires to carry a tint of purple, but the exceptional sapphire in Lot 1766 is displaying the purest of all blues, and appears to be almost inclusion-free under 10x loupe, which is extremely rare among Sri Lankan sapphires.

With over 95% of the sapphires being treated and enhanced nowadays, a natural Sri Lankan sapphire of over 20 carats is of great rarity, if in addition, it displays a pure and even blue colour with brilliant fire, one cannot overemphasize its importance. To be offered is an exemplary Sri Lankan sapphire with a bright saturated azure colour, completely free of heat treatment, this impressive 102.61-carat gemstone is without question a truly magnificent jewel of great beauty and rarity.

Sotheby's. Magnificent Jewels and Jadeite. Hong Kong | 07 avr. 2014 - www.sothebys.com