An early 20th century coloured natural pearl and diamond pendant, by Gillot & Co. Estimate CHF800,000 – CHF1,000,000($816,500 - $1,020,625). Photo Christie's Image Ltd 2015

Set with a brown button-shaped natural pearl, measuring approximately xx.xx - xx.xx x xx.xx mm, to the old-cut diamond surround and pendant loop, circa 1900, 5.3 cm, mounted in platinum and gold. Signed Gillot & Co. 

Accompanied by report and Premium Appendix no. 82347 dated 29 September 2015 from the SSEF Swiss Gemmological Institute stating that the pearl is a natural saltwater pearl, with no indications of colour modification; the Appendix on 'Exceptional Pearls' stating that this pearl '... exhibits an impressive size and weight (...), it shows an attractive brown colour with vivid rosé and green overtones'. 

Christie's. GENEVA MAGNIFICENT JEWELS, 10 November 2015, Geneva