Petrosapien

Petrosapiens ("Petro-" referring to rocks, "sapien" referring to the vague similarities to humans) are from the planet Petropia.

Physiology and Biology
While jewel-like in appearance, Petrosapiens are no pretty boys. Their diamond-hard bodies make these fearsome warriors incredibly tough. Shards of the razor-sharp crystals jut out at numerous odd angles from their heads and bodies, discouraging physical contact, and also act as powerful weapons that can turn a car into confetti in a matter of seconds. Combined with their increased strength, Petrosapien's shredding appendages can be especially devastating. Living prisms, Petrosapiens can refract light and beam-based weaponry, channeling them through their bodies and projecting them back at their source.

Weakness
Petrosapiens are particularly vulnerable to sonic vibrations. While a stereo blast might cause them to splinter, certain ultra-high-pitched sound waves can cause them to shatter - and no glue in this galaxy or the next can put a Petrosapien back together again.