Phrik

Phrik alloy was a rare metallic compound that was one of only a few lightsaber-resistant substances known. It was used in the polearms of IG-100 MagnaGuards' electrostaffs and Palpatine's lightsaber, as well as the armor of the Dark Troopers.

Major sources of phrikite have been found on Gromas 16 as well as the planet Oremin. Lesser deposits of phrikite have also been found on other planets, including Tatooine.

To make the durable phirk alloy, tydirium needs to be combined with the phirkite. Phrik is very expensive, and as a result sees limited use in warfare.

Information courtesy of Wookieepedia