As a rule of thumb, $1. 40 face value of scrap silver contains one troy ounce of silver. Recently, silver prices have been around $17. 50 per troy ounce. So, to get an approximate value for the silver bullion in your coins, multiply by 12. 5- a dime is worth about $1. 25, a quarter just over $3, and a half dollar $6. 25.