18ct Gold Single Stone Diamond Set Ring of Excellent Quality. The Round Modern Brilliant Cut Diamond of Top Colour, Est Colour G - H, Clarity SI, Great Sparkle. Est Diamond Weight 1.70 cts. Full Hallmark to Interior of Shank, Ring Size - I. Hallmark London 1999, Cost Over £10,000 20 years Ago. Excellent Colour and Great Sparkle, White Features to Interior of Stone, Cannot See with Eye. Please See Photo.