Idea: Inhib and nexus crystals should crack as they take damage

My favorite part of the new Summoner's Rift is how turrets fall apart and crumble as you smash them. (It's also great how they maintain their basic form until they finally explode: they just shed excess material / armor.)

It would be cool to extend this idea to the inhibitor and nexus crystals. At 2/3 health they start to crack, and at 1/3 health, the cracks grow. The cracking would sound like cracking ice on a frozen lake.

It would be really cool if the source of the crack was localized on the crystal according to which direction the damage was coming from, like bullets hitting bullet-proof glass. Of course, the crystals rotate, so I guess the damage would rotate.

Finally, something to consider would be maybe the light within the crystal starts to pulse as the crystal takes damage. The crystal holding the energy is taking damage and the containment becomes unstable. I think I've seen it in movies, when a containment field loses stability, the energy within pulses.