This is mainly determined by the nature of your raw material. SuperbMelt would like to inform you that gold bullion making is a different process compared to the refinery procedure. In addition to that, our vacuum casting machine does not refine your raw material. However, we can help you refine it if you are interested in such services. Therefore, you only get 999 purity gold bars if you give us a raw material that is extremely pure. To avoid disappointing our clients, we normally let them know these things before we start casting their gold and silver into bars. If the raw material is 999, then the finished product is also 999 and will not be subject to any pollution