18ct White Gold Lagoon Tourmaline and Diamond Ring

A statement cocktail ring centred on a substantial cushion-cut natural tourmaline weighing 12.496ct in a striking bluish green described in the trade as "Lagoon". The stone measures 16.95 x 10.08 x 8.56mm and shows the clean transparency and saturated colour that drives demand for this material at the upper end of the tourmaline market.
The tourmaline is set in 18ct white gold with double-claw fittings at each corner. The shoulders step up to the centre stone with a graduated arrangement of baguette and princess-cut diamonds in two tiers, an Art Deco-influenced architectural detail that frames the centre without competing with it.
Accompanied by a Bellerophon Gemlab certificate (Report A31835, 16 December 2025, Paris) confirming the tourmaline as natural with no indications of any treatment. Bellerophon is one of the leading European labs for coloured stone analysis. The certificate also notes "Lagoon" as the trade designation for this colour variation