A magnificent and rare natural pearl, emerald and diamond necklace. Price Realized CHF8,187,750 ($8,460,675). Photo Christie's Image Ltd 2013

The single-strand composed of twenty-three slightly graduated natural pearls, measuring approximately 13.7 to 10.4 mm, to the pear-shaped diamond and cushion-shaped emerald clasp, mounted in platinum and gold, 38.5 cm. Estimate CHF1,900,000 - CHF2,900,000 ($1,999,244 - $3,051,478)

Accompanied by report no. 66235 dated 4 January 2013 from the SSEF Swiss Gemmological Institute stating that 21 pearls are natural saltwater pearls and that 2 pearls are natural freshwater pearls, also stating that the emerald is of Colombian origin, with minor amount of oil; with an Appendix indicating that 'The natural pearls are very exceptional in their matching round to roundish shape and their fine pearl lustre.' 

CHRISTIE'S. MAGNIFICENT JEWELS, 15 May 2013, Geneva