What this coin looks like (obverse, reverse, mint mark location, special features, etc.):
One major variety is the 1879 CC Morgan Silver Dollar featuring a clear CC mintmark. This is the more common variety where the mintmark was struck clearly.
A rarer variety known as the Capped Die (or CC Over CC) variety features a coin being struck by a rusty die which resulted in a crusty mess around the "CC" mintmark. The difference between the 1879 clear CC vs Capped Die (CC over CC) Morgan dollar varieties is depicted below in the example comparison image:
Coin valuation chart: Typical coin prices, values and worth per grade or condition - in USD