Alaskan engineer has patented a novel approach for viewing anomalies hidden inside precious metals. This is the easiest and fastest way to see tungsten inside gold. It looks like an x-ray or MRI but is simpler, inexpensive and fool proof. These gold testers use a patented and novel Magnetic Susceptibility Imaging (MSI) technology. These MSI testers are used to detect and illuminate foreign materials concealed inside precious metals such as gold and silver. Thank you for looking and please ask if you have any questions.