It's called a blastia... And yeah, it replicates what a real heart does.

[He looks away gravely. Even with that whole beach incident when he first got here, he'd hoped he would be able to sweep that whole thing under the carpet. After all, they've all had much bigger worries on their minds.

Seems like he's really just having crummy luck here.]

I lost the original a long time ago. I don't really have a choice but to get by with it.