There are a few specialty stores which deal in buying and selling certain items. The coin dealers Rockville residents will find at these stores will purchase certain types of coins people bring in. These coins usually need to be made of gold or silver or have an unusual property. Rare coins can be purchased by this type of dealer as can coins minted with flaws in them. People who have coins from other countries, might be able to sell them as well, if they are rare, or contain a certain amount of a precious metal. In addition to buying these unique coins, this dealer will also have them available for sale.