Actually the rings are probably casted in silver and are not only coated by the metal. Usually the process for this kind of jewelery is like this: 3D Model --> casting wax --> make negative of wax model in plaster --> cast precious metal in to negative model --> finish product (polish/highlight/...) So the material worth of the jewelery can easily be quite high if you cast e.g. rose silver... The process is pretty well described at i.materialise: https://i.materialise.com/3d-p...

I agree this is hardly any news, the concept of using "sound waves" for jewelery is used by multiple other vendors, there are even people selling basically the slashverdised product on etsy: https://www.etsy.com/de/search... No news here...