While newer collectors prefer their silver coins in mint condition, many others prefer the character and natural beauty of a toned coin. In fact, toned coins are often considered more valuable than their shiny, new-looking counterparts. Professional coin graders can almost always detect whether a coin has been artificially toned, but coin collectors sometimes tone their coins anyway to enhance aesthetic appeal or to mask scratches and other impurities.
Place the coin in an envelope and seal it, or wrap it in a paper that contains sulfur.
Set the wrapped coin on a windowsill and allow it to sit for a month or longer. This is the easiest way to give a coin some toning. For deeper toning that can cover some scratches, you can use an oven.
Set the coin on a baking sheet and put it in the oven.
Bake the coin on both sides at a low temperature setting. Keep checking on the coin until it has achieved the desired level of toning.
Turn off your oven and allow the silver dollar to cool before handling it.