A Belle Epoque ruby and diamond ring, by Boucheron. Photo Christie's Image Ltd 2014

Set with an oval-shaped ruby, weighing approximately 5.52 carats, to the diamond-set line shoulders, 1910s, ring size 7, with French assay mark for platinum. Signed Boucheron. Estimate CHF350,000 – CHF450,000 ($400,845 - $515,372)

Accompanied by report no. 72506 dated 23 January 2014 from the SSEF Swiss Gemmological Institute stating that the ruby is of Burmese origin, with no indications of heating

Report no. 14040064 dated 15 April 2014 from the Gübelin Gemlab stating that the ruby is of Burmese origin, with no indications of heating, and two Information Sheets on Unheated rubies and Mogok rubies

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