Velmorite

Velmorite was a yellow lightsaber crystal found only on the planet Velmor. They were used to produce high quality Velmorite energy swords, though other applications were certainly possible.

When used in a lightsaber, this crystal created a fine, thin blade for graceful, fluid wielding.

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