Nilrebmah X was a rocky planet in the Nilrebmah system. The planet's atmosphere of sulfur dioxide. Lacking any surface water, the planet was home to a silica-based life form that were capable of touching the Force. Incapable of locomotion, these creatures were united through a type of telepathic mind, which allowed them to project their emotions into the collective.
Around the time of the Hundred-Year Darkness, the Sith Lord Ku'ar Danar enslaved the people of the moons of Nilrebmah II and sent them to quarries on Nilrebmah X. The slaves mined the planet for its Force-sensitive silica-based creatures and transported them to Nilrebmah XIII to construct a massive monolith.