Silver bars can be purchased in a variety of weights and sizes. Silver bars commonly come in the standard sizes of 1 oz., 5 oz., 1 kilo, and 100 oz. The larger the size of silver bars you purchase, the lower the price per ounce you should typically expect to pay. Silver rounds are very similar to silver bars with the only main difference being they are typically available in 1-ounce sizes. Silver rounds that are minted in sizes larger than 1 oz. are very rare.
Silver Bars and Rounds with a fineness of 0.999 and higher are IRA-approved.