I think the main difference between them though is that Raven is more tormented with what she can do. So far, Amethyst being an Earth-gem hasn't really made her any different from others. Not that we've seen anyway. For Raven, she was constantly battling herself to not let her emotions and powers run rampant, as well as having the knowledge that she'd cause the end of the world.

Though, it could be kind of interesting for Amethyst. Maybe Earth-gems have a kind of mind control element that could turn her against the others? Be kind of frightening to learn. That everything you are can be snatched away at any moment should Peridot or any other gem fix up the place and activate it.