Super Missile Block

Super Missile Blocks are a type of destructible block that appear in Super Metroid and Metroid: Zero Mission. Super Missile Blocks appear identical to other blocks around them, unless uncovered by a Morph Ball Bomb, Power Bomb or X-Ray Scope. Only Super Missiles can destroy them.

Super Metroid Manual
"Blocks that shows the Super Missle icon can be destroyed by Super Missle."

Metroid Zero Mission Manual
"Super Missile are the only weapons that can destroy these durable blocks."