how many grams are in a troy ounce of silver
First weigh it in grams or standard ounces. 1 troy ounce is about 31.1 grams or 1.1 standard ounces, â¦so divide by either of those numbers as appropriate, to get troy ounces. Coin silver is an alloy of 90% pure silver and 10% copper so multiply the final result by 0.90 to get the amount of pure silver. 3 people found this useful.