Basalt

Basalt was a rocky substance found on multiple planets, including Iego and Pamarthe. Many of Pamarthe's islands possessed basalt cliffs, with some featuring spaceports carved into them. Iego's surface was covered with basaltic spires, and many of those spires had cities, such as Cliffhold, built within them. One type of basalt, known as flood basalt, could be found on the volcanic world of Mustafar. A forest of basalt pillars was present on the planet Koboh, drawing the fascination of High Republic Era scientists.

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