Sometimes, new collectors assume that a historic silver coin will shine as brightly as it did when it was manufactured. While this may be the case with gold, silver is another affair entirely. Silver does tarnish when exposed to the atmosphere. It reacts with sulfur, which produces a distinctive type of tarnish on the surface of the coin. Before you panic, realize that the coin is not being eaten away by this tarnish as your fenders are eaten away by rust. The tarnish is only on the surface of the coin; it is not the same thing as corrosion.
A silver coin that has been around for many years will inevitably be dull in color. At the early stages of toning—as this process is called by numismatists—the silver may take on a rainbow-colored tint. It’s actually quite beautiful. Over time, the silver will blacken. Eventually, it will become almost completely black. If you were to remove the toning from the silver, you’d find the surface underneath unscathed. However, removing this toning instantly diminishes the value of the coin. Never clean off a toned silver coin; it does not increase the value in any way.
Your silver coin should be protected from handling. Because so many collectors’ coins are historical, it’s tempting to take them out of their case. For whatever reason, touching something very old tends to make human beings feel a profound connection with the past. It’s fun to imagine how someone handling your Morgan Dollar, for instance, in the 1800s would have no way of knowing that you’d be handling the same coin more than a hundred years later, and that connection is profound. It also ruins your coin. Leave them in the slab they come in to keep them as well preserved as possible.
Sometimes you can buy a silver coin at a price low enough that buying in quantity makes sense. Morgan dollars are oftentimes sold in this way, as they make good bullion investments but some years are so common that they don’t merit certification. These coins are usually fine to handle. If you want to learn a bit about toning, notice how two coins of the same age can sometimes exhibit vastly different levels of tarnish on them. This simply has to do with how they were handled and preserved over their many years of existence.