Zebetite
From Wikitroid, the Metroid wiki
Zebetite is a powerful ore. Shields of Zebetite are located in Tourian, protecting the Mother Brain. Although they are easily destroyed with Missiles, Zebetite shields regenerate over time. They are featured in Metroid, Super Metroid, and Metroid: Zero Mission. Also, objects resembling Zebetites which also diminish in thickness when fired at appear in some Space Pirate facilities in Metroid Prime 3: Corruption.
In Metroid (manga), Mother Brain states that Zebetite is a mineral that can deflect particles, rendering Samus' power beam useless.
