A sapphire single-stone ring

A sapphire single-stone ring
The cut-cornered rectangular sapphire, weighing 11.92 carats, in claw mount to baguette diamond single stone shoulders, mounted in platinum, hallmarked London 2004
Accompanied by report No. 03022 dated 8 July 2010 from The Gem and Pearl Laboratory, London, stating that the sapphire was natural and that no evidence of heat treatment was observed