Beskar

Beskar, also known as Mandalorian iron, was a curiously strong metallic substance that could only be found on the planet of Mandalore. When the Taung first arrived on this world, they soon discovered the unique properties of this supermetal. It wasn't long before they figured out how to make cool-looking armor and helmets using the stuff, not to mention vicious-looking melee weapons. Far into the future, they would even make clunky, slow-ass effective combat transports using beskar. The material was highly resistant to all forms of energy, be it from a blaster or a lightsaber.

Beskar was also highly prized by Fandalorians, who wished they had some in order to make cool cosplay outfits and fanon costumes. It was rumored that Karen Traviss had the only sample of beskar which was known to exist. However, when she produced the sample, it was cut in half by a common butter knife, proving that it was actually lithium made to look like iron.