Cortosis ore is a rare lightsaber-resistant mineral in Star Wars canon. When a lightsaber comes in contact with the mineral, the cortosis forces the energy of the lightsaber blade back into itself, causing the lightsaber to temporarily short out. In addition to shorting out lightsabers, cortosis also dissipates the energy of a blaster bolt and redirects the energy of explosions. The cortosis mineral is brown and comes from the planets Dinzo and Mokivj.
In Star Wars legends, cortosis was used to create gauntlets, armor, shields, vibroblades, and other weapons. Lightsabers could cut through cortosis after repeated strikes. Jedi Master Shadday Potkin fought against Darth Vader with cortosis blade. Although the Jedi Master’s cortosis blade successfully shorted out Darth Vader’s lightsaber, Vader grabbed the Potkin by the neck, snapping her spine, killing her instantly.
Cortosis first appeared the novel I, Jedi (1998) by Michael Stackpole, a book which is now part of Star Wars legends. Cortosis was reintroduced into Star Wars canon in the novel A New Dawn (2004) by John Jackson Miller.
COVER IMAGE CREDIT LucasArts/BioWare
Image depicts a deactivated lightsaber from the Star Wars: The Old Republic trailer ‘Deceived’.