This might sound crazy, but humans don't get shiny rocks for birthmarks.

[He's not quite done investigating yet, still reaching at his own neck. After a little effort, he pulls his Shard free, and stares at it like it's a bizarre foreign object... and yet somehow not at all. Even disconnected like this, it feels like part of him.

He holds it up to the light, observing it from different angles.]

...It doesn't hurt to take out, so long as you're gentle with it. You're probably safer taking yours out in human form, though -- they look fragile.