Petropia

Petropia is a craggy, geode-like planet where silicon-based beings called Petrosapiens evolved to build a complex society of underground kingdoms. After several centuries of warfare, a giant hole was ripped in the sky, revealing a universe far beyond Petropia's heretofore self-contained existence. As the recently enlightened Petrosapiens have now begun to turn their focus off-world, the rest of the galaxy holds their breath, waiting to find out if Petrosapiens will wage war or come in peace.

Notable Inhabitants

 * Diamondhead
 * Tetrax
 * Chromastone
 * Sugilite

History
Petropia was once destroyed by Vilgax, but it was revived with all its inhabitants in The Secret of Chromastone, by Diamondhead (although it was destined to be Sugilite's mission).

Petropia is guarded by Sugilite.

Ben 10

 * Ben 10: Secret of The Omnitrix (flashback)

Alien Force

 * The Secret of Chromastone