Really? Huh. I would've thought they'd be fairly universal. Maybe you just have a different word for them.

Mako is a liquid, like I said before. When it condenses enough, it crystallizes. That's how you get materia.

Here, I'll show you a picture.

Kunsel switches to video briefly, with the camera pointed at his arm. There's a bracer there, with three materia slotted in. All three of the little glass-like marbles are green, almost seeming to glow in the dim morning light.]