Edwardian Emerald and Diamond 15K Yellow Gold and Silver Ring. Oval 15K (acid tested) yellow gold and sterling face emerald and old mine cut diamonds ring. The emerald is a lovely color with natural inclusions. Lots of open work in sterling as a lovely background for the diamonds. The square central emerald is surrounded by 12 diamonds set in the open sterling work. Diamonds were set in sterling at that time as a way to highlight their glitter. The back of the ring is yellow gold in a basket motif. The ring is marked 750 indicating 18k gold but my test indicates 15K so I am listing it that way. Size 7 3/4 US. Minimal wear. A lovely ring to add to your collection of rings.