I remember reading on a blog or a news article on the internet once that sometimes counterfeiters have made fake silver coins and silver bars out of molybdenum. Silver is worth far more than molybdenum. Counterfeiters made fake silver out of molybdenum because they could acquire the molybdenum for a low price and then sell the molybdenum at silver prices. The source said that the electrical and thermal conductivities of molybdenum are far different than the electrical and thermal conducitivities of silver, and that is how one can use certain tools to differentiate silver from molybdenum. I cannot find the old source on the internet. What tools can be used to differentiate silver from molybdenum by looking at thermal and electrical conductivities?