Sterling SilverThis Amica ring is handmade in 10k yellow gold with a sterling silver band. The central-set semi-precious gemstone is an emerald cut sky blue topaz.12.56ct sky blue topaz measuring 15x12mm. Available in sizes L, M, O, and P.Inside diameter of size L is 16.1mm. Inside diameter of size M is 16.51mm. Inside diameter of size O is 17.35mm. Inside diameter of size P is 17.75mm. Certified in accordance with the Hallmarking Act 1973.