[@Mr Allen J]Yeah, that did come to mind, buuuuuuuut . . . Superpowers? I just liked the idea, and like I said, it's kind of enhanced crystals, which was my explanation of why they are so durable, if you want, I could change it to rock, but rock is boring, Crystals are awesome, my thought process is a nutshell. As for the crystalizing, I can get rid of it. He wasn't going to use it much anyway, so it's no sin off my bones.

Edit: That reminds me, bullets that can break his armor would be armor piercing rounds and most sniper rounds. Armor piercing because that's what they do, and sniper rounds cause sniper rifles have a lot of power. Shotguns could work to, if they are close enough or are Single Slug rounds.