Runic Block

A Runic Block can be crafted from nine runic bricks, which must be mined with a rune or dragon pickaxe inside a nether fortress. Runic Blocks have a few interesting properties that make them useful: firstly, they have near infinite blast resistance (the same as bedrock), so no creeper or TNT explosion can destroy them. Secondly, they are unreturnable - even a dragon pickaxe will not return the original block after mining it. For this reason, a player must be very careful when placing runic blocks, although they can be very useful blast-proofing barriers if used correctly.