Capitalization Questions

The two kinds of silver dollars that are popular with collectors are the Morgan dollar and the peace dollar. Morgan is a proper name, so I get that it should be capitalized. But what about the peace dollar in this context? Should “peace” be capitalized.

Also, what about sterling silver? Is “sterling” a brand name or something?

It’s a question of style. Different people will come up with different answers.

No, sterling silver is an alloy of silver and other substances, just like steel is an alloy of iron, copper, and other substances, and brass and bronze are alloys of copper with zinc and tin.