Urthic ore composes most of Zebes's crust and was briefly mentioned in Metroid Prime. It is considered "ideal for subterranean construction." The official website states that Bendezium is "commonly found on planets with crusts containing 85% or more Urthic ore." [citation needed]

Metroid manualEdit

"The planet Zebes is a natural fortress. Its sides are covered with a special kind of stone, and its interior is a complicated maze."