Pure silver has a millesimal (parts-per-thousand of pure metal by mass in the alloy) finess of .999 containing 99.9-percent silver. There is no 100-percent pure silver, as impurities that are impossible to remove constitute the remaining amount. The industry standard for purity since the early 1970s is .999 fine, although some refiner’s bars will assay much higher. Bullion bars and specialty coins, or rounds, are made of pure silver but generally pure silver is too soft for commercial use. Evaluating pure silver depends upon its form.
Assess a silver bar by reading its imprint which indicates the minting location, weight and level of purity. For example, an imprint that reads “.999 Fine Silver, 10 TR OZ” indicates that the bar is 99.9-percent pure silver and weighs 10 troy ounces.
Take other forms of silver to an assay laboratory where it can be tested to evaluate the percentage of purity using fire or chemical tests, and weighed.
Evaluate the monetary value for bars and coins by checking the current market price of silver per ounce. There are many websites that list this information such as www.Kitco.com. If spot silver is at $44 per ounce and you have a 10-oz. bar, that bar is worth $440.