A single stone diamond ring

A single stone diamond ring, the oval brilliant-cut diamond weighing 1.00 carat, of F colour, VS1 clarity, GIA certificate number 10572176, four claw-set to a tapered square-section shank with diamond-set shoulders, hallmarked platinum, London 2006, bearing the Bentley & Skinner sponsor mark, gross weight 3.6 grams

No. 19090V