Stygium

Stygium was a type of crystal only found on Aeten II and Maramere.

Stygium crystal cloaking device
The Galactic Republic, in 22 BBY, passed a law controlling the trade of stygium, as it was a crystal that, when used properly, could entirely cloak a vehicle. In the Galactic Republic's early years these devices were common, since Aeten II held an abundance of them. These vehicles included the Scimitar, Darth Maul's ship, which carried an array of stygium crystals in its long prow.

Darth Vader's secret apprentice, codenamed Starkiller utilized styguim crystals in his ship, the Rogue Shadow, which used a cloaking device.

During the events from the capture of the Tantive IV to the Battle of Endor, Grand Admiral Martio Batch sent an Empire superweapon to Aeten II, the Tarkin. There, the Tarkin blew open the planet to reveal its stygium core.

Using the crystals and the original stygium implementation, he started the Phantom TIE project. However, saboteurs from the Rebel Alliance destroyed the project and Batch fled. The use of stygium crystals stopped after the creation of the New Republic, although they were still available from Aeten II.

There was also an entire island on Maramere composed of the crystals, which made it invisible to scanners. Since the island was also covered with the fog surrounding the Haunted Strait, the island was also invisible to the eye, making it the perfect hideout for Sol Sixxa.

Stygium lightsaber crystal
In its pure crystal form, it was known to be suitable for use as a lightsaber crystal. It was known that when refined Stygium was mounted on a personalized lightsaber and wielded by a Force-sensitive, the natural cloaking attributes of the crystal would augment the power of a stealth-minded Jedi in remaining unseen.

Behind the scenes
In order to corrupt Aeten II in Star Wars: Empire at War: Forces of Corruption, the player can select the mission "Piracy" to begin a battle involving Bossk and a small Zann Consortium fleet destroying some Stygium Crystal containers. This allows the player to build TIE Defenders for the Zann Consortium.

Appearances

 * Star Wars: Knights of the Old Republic II: The Sith Lords
 * Darth Maul: Shadow Hunter
 * Single Cell
 * Star Wars Episode I: The Phantom Menace
 * Starfighter: Crossbones
 * The Force Unleashed novel
 * Star Wars Galaxies
 * Star Wars: Empire at War
 * Star Wars: Empire at War: Forces of Corruption
 * Star Wars: Empire at War: Forces of Corruption