Fortune only affects non-block item drops, not the block item drop themselves. A block cannot drop 2 blocks, otherwise it would be an unintended duplication glitch.
By definition, Fortune affects the loot table of blocks when broken by increasing either the chance that non-block items are dropped, or the number of non-block items dropped. This means that only blocks programmed with a loot table that includes changes to drops from Fortune will be affected by the enchantment. Blocks that always drop blocks (like stone to cobblestone) or themselves will never be affected by Fortune.
Fortune only affects non-block item drops, not the block item drop themselves. A block cannot drop 2 blocks, otherwise it would be an unintended duplication glitch.
By definition, Fortune affects the loot table of blocks when broken by increasing either the chance that non-block items are dropped, or the number of non-block items dropped. This means that only blocks programmed with a loot table that includes changes to drops from Fortune will be affected by the enchantment. Blocks that always drop blocks (like stone to cobblestone) or themselves will never be affected by Fortune.