http://coin-cleaning-service.merschat.com : This shipment of corroded coins contained mostly quarters and nickels, some dimes, very few penny (cent) pieces, and miscellaneous debris. Some, like the nickel at left-center looked almost fine, while most were heavily corroded, tarnished, and dirty. If you have a few pounds or more (up to thousands of pounds) of old coins like this, why wrestle with cleaning them yourself? It's a lot of work. Our process took years to develop.