Petrosapien

Petrosapiens ("Petro-" referring to rocks, "sapien" referring to the vague similarities to humans) are from the planet Petropia (a portmanteau of "Petro-" and "Utopia"). Petropia is a crystal-covered world, and its inhabitants are silicon-based life forms whose bodies are formed entirely out of opaque gemstones and whose rock-hard physiologies make them all virtually invulnerable to physical attack. The majority of its inhabitants live in underground kingdoms. The different types of gems denote different races, each with its own distinct abilities and culture, and most Petrosapiens coexist peacefully. Beforehand, there was a centuries-long war between them, which led to their inadvertent discovery of space. This stabilized their civilization, and they began to explore beyond their planet.

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.