Spice indigenous only to the planet Arrakis in the Frank Herbert masterwork Dune.
Melange is the most valuable commodity in the universe, enabling interstellar travel by allowing members of the Spacing Guild to guide vessals without striking dangerous objects. The avoidance technique involves utilizing prescience to guide the Guild's spacers along clear lanes. Guild pilots are inundated with melange saturated gases to stimulate their prescient abilities. The spice is highly addictive and only individuals with a high tolerance can withstand the negative effects of the narcotic. A symptom of melange addiction is a tell-tale blue-within-blue coloration of the eyes of the user.
Melange possesses other properties as well as stimulation of prescient abilities. It extends the life of those who regularly use it. Melange is decribed as a geriatric 'awareness spectrum' narcotic. One of the dangers inherent in a narcotic which stimulates an 'awareness spectrum' is the danger of becoming lost within that very spectrum. Users must be able to maintain internal cohesion and integrity to withstand this effect.
A third important aspect of melange is its use in creating the Water of Life. This substance is both potent and poisonous, and is created by drowning a small sandworm, which in its death secretes the substance. Ingestion will kill the consumer unless they are able to awaken their inner ability to transmute the substance into a harmless form. In this process an awakening occurs, an awakening of a genetic memory containing the experiences and knowledge of all forebears. This awakening is employed by the Bene Gesserit in a ritual which creates Reverend Mothers.
Melange creation and production
Melange is a byproduct of the life cycle of the huge sandworms native to Arrakis. In a larval stage the worms (known as sandtrout at this phase of their development) gather in large masses beneath the desert sands, creating the spice as a byproduct of their biological processes. It is expelled in a dramatic geyser effect known as a spiceblow, an explosion of gases, sandtrout, and the spice itself.
The spice is spotted (usually from the air) due to its distinctive coloration and its concentration on the surface. Harvesting machinery is then dispatched to gather the spice in a race against destruction. The sound and vibration of the harvesters create a rhythmic signal summoning mature sandworms to defend intrusion into their territory. Mature worms can reach a length of several hundred meters. Their size, coupled with their almost indestructible bodies and their mindless destructive reaction to maurauders, make spice harvesting both deadly and incredibly lucrative.
Melange and politics
Melange is a product of Arrakis, and the only place in the universe where it is naturally produced. He who controls Arrakis controls the spice, and therefor the tremendous economic and political power it commands. Thus politics enters upon the scene, pitting the Great Houses one against another in a bid to secure their fortunes and futures by controlling the commodity. Most notable are the fortunes of House Harkonnen and House Atreides as relating to melange.
In a move which pits House Atreides against House Harkonnen, the Emperor unwittingly sets the stage for the creation of the Qwisatz Haderach, a male possessing all the memories and abilities of a Reverend Mother. In an effort to escape Harkonnen destruction, the Lady Jessica, (bound concubine of Duke Leto Atreides), and Duke Leto's son and heir Paul Atreides flee into the Arrakeen desert. There they encounter the Fremen, natives of the desert planet. Winning first a place, then a leadership role among the Fremen, Paul and his mother lead the natives on a jihad which eventually topples the Emperor himself and leads to altering the path of the entire known universe.
Farther along in the Dune
saga a method of synthesizing melange is developed by the Tleilaxu
, who sought to break the monopoly held by Arrakis for spice production. Their success brought their destruction by the Honored Matres
, who also destroyed Arrakis in a bid to end the spice altogether. They were in turn thwarted by the Bene Gesserit, who escaped Arrakis with a single sandworm, preserving the source of natural spice production.
Meanwhile, back on Earth...
In the much more prosaic and therefore much less interesting world we currently reside in, melange also exists. It is a blend of terrestrial spices used in cooking and as a rub for roasting and/or barbecuing meats.
Sources of melange are easily found by using your search engine as well as being available at various purveyors of culinary supplies.