Sterling Silver, 10k/14k/18k gold, Platinum The stones are Opal and diamond. The center opal is about?6.5mm Round cut The stones can be replace with other gemstones.For example,if you don't like the CZ accent,you can ask me replace it with tourmaline,aquamarine,diamond,emerald,sapphire... For custom making jewelry,it can be made in 2 different metal. 1,Solid gold,including 14/18k white/rose/yellow gold. 2,925 sterling silver with white/yellow/rose gold plated. High quality with 30 days return policy. Quality takes time,please allow 3-4 weeks for me to make your jewelry!