Honestly, I don't know. That's probably why I haven't managed much more than "make it sparkle." And I'm not even entirely sure what a single Emerald can do... Shadow used his to warp time and shoot deadly light beams, the other Shadow...

[Shakes his head. No, let's not talk about that.]

Knuckles had a great big green one that could float a huge island.

What's in it for you... chance to check out a fancy battery, I guess. Just don't attach it to a rocket. I'll want it back.