A conch pearl and diamond necklace. Photo Bonhams

comprising three strands of forty-four, forty-seven and forty-nine graduated conch pearls, measuring approximately 12.4 to 3.3mm., with seed pearl and diamond rondell spacers, completed by an oval, square and old European-cut diamond clasp; estimated total diamond weight: 1.00 carat; clasp mounted in platinum; length: 18in. Lot 175. Estimate: US$ 300,000 - 350,000 / £190,000 - 230,000 / €240,000 - 280,000

Accompanied by SSEF report #62139, dated February 16, 2012, stating: 140 natural pearls including natural conch pearls, no indications of artificial color modification.

Bonhams. 13 Jun 2012 noon New York. Fine Jewelry