Long ago a blue giant went supernovae leaving behind the broken husk of a star, a white dwarf. Because of the materials left behind from the planets previously in this system new planets formed, including Shal'nar. Because of being tidally locked one side of Shal'nar was a molten ocean of lava with tiny islands of volcanic rock, and on the other side was vast expanses of ice, only in the band of twilight did the Kaoom and all other life grow and flourish.
On the outskirts of the twilight zone due to the rapid cooling of lava, there are massive islands of obsidian, this has caused many of the ancient Kaoom's tools to be made of obsidian. Unfortunately, Shal'nar seems to be void of metals and this has caused the Kaoom's early spaceships to be made of the metallic carapaces of the insectoid creatures that roam on Shal'nar.