Koh Nur

Koh Nur, or the Mountain of Light, was a giant opal kept in the heart of the Great Khan's palace in the Sevenfold Mazework of the Great Dismal Delve.

Description
The light emitted from Koh Nur was the method of timekeeping with the Sevenfold Mazework and the entire expanse of the Great Dismal Delve. The light also illuminated the entire area.

Twice a day Koh Nur would change color, from light orange to rich purple. The beginning of morning was marked by the orange light trickling from the Mountain of Light and lasted for approximately 13 hours, at which point the light changed to purple and lasted for the same amount of time. All light from Koh Nur was reflected from other strategically placed gemstones located throughout the entire region of the Great Dismal Delve.

Rumors and Legends
Tampering with or destroying one of the gemstones reflecting light from Koh Nur was punishable by a fine a 500 gp and a year of servitude to the Great Khan.