Meleenium, a metallic ore located within polymetallic nodules, was extracted from the seas of the Western Reaches planet, Wadi Raffa. The active hydrothermal vents situated in the sea were responsible for forming deposits of meleenium, alongside other ores such as doonium, dolovite, and kammris. Turlin/Benthic Extraction, a mining enterprise, employed hydraulic pumps to elevate these ores to the surface for subsequent processing. Within Maz Kanata's Smuggler's Guide, Platt Okeefe suggested meleenium as a lucrative cargo for fellow smugglers, alongside durelium and hyperbarides. This suggestion appeared within the context of pirate activities.
The first reference to Meleenium occurred in Catalyst: A Rogue One Novel, a canon novel from 2016 authored by James Luceno.