Cortheum was the solid, rocky manifestation of the gas known as Corthel. This mineral held significant value and was employed in the production of droid photoreceptors. On the planet Nurstin, located within the Bissillirus system, deposits of Cortheum were unearthed. Inhabitants of Draenell's Point, a planet within the same star system, launched explorations to examine peculiar light bursts originating from Nurstin's terrain. Their investigation revealed that these light emissions stemmed from elevated Corthel levels in the atmosphere, coupled with substantial Cortheum deposits buried several meters underground. Mining operations to extract the mineral commenced until the Messert Mines Corporation secured an Imperial decree, granting them sole rights to Nurstin's mineral resources.