Sun opal

Sun opals were a semiprecious gemstone found on the planet Dalna. The stones could capture and refract sunlight, making them useful for illumination. Veins of the stones ran through the caverns in the compound inhabited by the Path of the Open Hand, and several chambers were positioned so they could be lit with the stones. The cult also made patterns with gathered opals on a hillside in the compound.

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