For a resource like this, you should have 2 layers:
One for the stone, one for the glow. That way, the programmer can let the glow fade in or pulse.
In an ideal world, your glow would be grayscale, so the programmer could modulate the glow (maybe one of those things is a health recovery, and another is an MP recovery, or a save spot---different colors mean different things---maybe a faster pulse means it has a greater effect, &c &c).