A natural pearl, cultured pearl, and diamond brooch. Photo Christie's Image Ltd 2014

The top designed as a pear and marquise-shaped diamond cluster, suspending a detachable white natural drop-shaped pearl and a grey cultured drop-shaped pearl, measuring respectively approximately 11.4-11.5 x 21.2 mm and 11.0-11.0 x 21.7 mm, 4.9 cm, with French assay marks for platinum and gold. Estimate CHF230,000 – CHF320,000 ($263,035 - $365,962)

Accompanied by report no. 73707 dated 28 March 2014 from the SSEF Swiss Gemmological Institute stating that the white pearl is a natural saltwater pearl, and that the grey pearl is a cultured saltwater pearl, with no indications of artificial colour modification 

Christie's. GENEVA MAGNIFICENT JEWELS. 14 May 2014, Geneva- http://www.christies.com/