Kelbium and Zafrite

Kelbium and Zafrite are two types of ore described in unused scan data from Metroid Prime 2: Echoes. Both are vulnerable to different weapons: Kelbium can be destroyed by Super Missiles, and Zafrite can be melted with the Light Beam.

The mechanic of a Super Missile being used to destroy a sort of obstruction was first seen in Metroid Prime, when Samus occasionally had to use her Super Missiles on Cordite objects. The mechanic of being able to melt materials was reused in Metroid Prime 3: Corruption, where metal obstructions could be melted using the Plasma Beam.

Unused Inventory data
"Super Missiles can destroy objects made of Kelbium."

"The Light Beam can be used to melt and destroy certain materials, especially Zafrite."