Bomb Blocks are a type of Destructible Block that is destroyed by Morph Ball Bombs or Power Bombs. They appear in Metroid Fusion, Super Metroid, and Metroid: Zero Mission, and are somewhat replaced in the Prime series by Sandstone and Talloric Alloy, though since the Destructible Blocks' material in the 2D Games is not revealed, it is possible that they are made of one of these materials.
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As seen in Metroid Fusion.
As seen in Metroid: Zero Mission.