In James Cameron’s Avatar, humans mine a valuable mineral called unobtanium on Pandora. The fictional material is the main economic reason for the Resources Development Administration’s operation there.
The plot places the human mining project in conflict with the Na’vi, especially the Omatikaya clan, whose home stands above a rich unobtanium deposit. The mineral’s value drives the attempted removal of the clan and supplies the central political and environmental conflict.
“Unobtanium” is a long-standing engineering term for a hypothetical material with exceptionally desirable properties. Cameron’s film uses the word as the name of a rare fictional mineral rather than inventing the term from nothing. In the film’s setting, unobtanium is valuable because of its unusual magnetic properties and enormous commercial price.
The material is not the same as Marvel’s adamantium or DC’s fictional substances. Those belong to different fictional universes and are unrelated to Pandora in Avatar.