This is a unique artisan cuff bracelet that is both 999 silver and 925 silver. Cuff is 2 layers stacked on each other. The top part is 999 silver which is generally used when using keum boo. For the traditional Korean technique of keum-boo, fine silver (99.9% pure silver) is generally used because gold atoms diffuse and bond directly into pure silver at a microscopic level. Sterling silver (92.5% silver) can also be used, but it requires a pre-treatment called depletion gilding to bring a thin layer of pure fine silver to the surface first. So the top plate is 99.9% silver with gold keum boo applied to it. There is a small Australian opal bezel set in the center of the cuff. The base layer of the cuff is 92.5% silver which is generally called sterling silver. Cuff sits at a size 6 on the bracelet mandrel. It can be stretched a little but not too much. The inner circumference is 5 inches with a gap of 1.05 inches. I wear a size 6.25. It fits upto a size 6.5. It is marked with a maker's mark that looks like an intertwined JF with .99 script signed. Cuff weighs 32 grams. Stunning artisan piece. Do not know who the maker is. I am not sure what type of opal it is but it is blue with multicolors showing. Looks like a black opal or crystal opal doublet. The opal is 0.5 inches wide. Cuff is 0.6 inches wide. Has patina that is lightly polished. I don't polish pieces clean. That is upto the buyer.