Beskar

Beskar, also known as Mandalorian iron or Mandalorian steel, was an alloy that was used in Mandalorian armor and was notable for its high tolerance to extreme forms of damage. In its purest forms, the metal was durable enough to withstand a direct blaster shot and could repel lightsaber strikes. A superweapon created by the Mandalorian Sabine Wren and used by the Galactic Empire, called the Arc Pulse Generator, was capable of superheating the metal to the point that it would burn everything it was protecting to a crisp, such as Mandalorian warriors encased within their beskar armor. However, Wren destroyed her weapon during the Mandalorian Civil War.

Text and facts from the “Beskar” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.