Junk silver is kind of like the leftover pieces of silver coins that were used in the past but are no longer used. They are called junk silver because the coins are worn down and not used anymore. When people buy junk silver, they are buying it for the silver inside the coins, not for their collectible value. Junk silver coins are bought by weight. For example, 1 ounce of junk silver coins is equal to 28.35 grams of silver.