The cabochon cat's eye alexandrite, weighing 19.41 carats, within a surround of brilliant-cut diamonds of brown tint and briolette-cut diamonds of yellow tint, accented by brilliant-cut diamonds to the hoop, diamonds approximately 5.35 carats total, ring size 4

Accompanied by a GRS report stating that the natural cat's eye alexandrite has no indication of heat treatment and changes from Green to Purplish-red colour. Report number GRS2013-052870, dated 13 May 2013. 

Bonhams. RARE JEWELS & JADEITE, 30 Nov 2016, 15:00 HKT - HONG KONG, ADMIRALTY