Possibly, a block which is compressed reinforced stone? You use a compressor on reinforced stone, and get a reinforced stone chunk. Four of these make a single compressed reinforced stone, which has (4^1.75)*compressed stone's resistance.
It would take 15 seconds to mine with a diamond drill. (would it need to be immovable by pistons?)
If you can't make a door form it, it should be piston-movable, otherwise, it should be immovable.