With the ever rising gold prices, buying and selling gold has never been such a profitable business. Whether you are buying or selling gold, silver, and diamonds, a tester is a good idea to back up any decision about the value. Gold testing and silver testing can determine if you are going to make money or loose money. By testing for gold you can figure out if you are holding on to something worth hundreds of dollars or just a look-a-like. Experienced goldsmiths and jewelers can see tell-tale details with some jewelry, but usually use metal testing devices to be sure of their decisions.