Blades considered this. "Basically, ya're sayin' it might have been either unusual natural circumstances involvin' magic in the ground or somepony castin' spells on it? 'Cause the latter... Well, we've got that subterranean pony who might've been able to do something like that, although I don't know if she'd be into makin' magical metals like that, but she might be able to do that kind of thing, 'cause there's a lot of power she's got there. "