The most important resource harvested from Arrakis is the drug melange, commonly called the spice.
In Frank Herbert’s Dune, melange is found naturally only on Arrakis, the desert planet also known as Dune. Its rarity and unique properties make the planet the center of political and economic power in the Imperium. Whoever controls Arrakis controls the supply of the universe’s most valuable commodity.
Melange extends human life and produces heightened awareness and prescient abilities. Most importantly, it enables the Spacing Guild’s Navigators to foresee safe routes through folded space, making long-distance interstellar travel possible. Without the spice, the Imperium’s worlds would become effectively isolated.
Harvesting melange is extremely dangerous. It forms through a biological cycle involving the sandworms and pre-spice masses beneath Arrakis’s sands. Mining crews use specialized harvesters, but rhythmic vibrations attract enormous sandworms, which can destroy equipment and consume workers. The spice is also highly addictive, and withdrawal can be fatal.