Voidstone is mined at the same speed as stone, with any pickaxe. It drops cobblestone when mined. It also has a 2% chance to drop a Bedrockel Nugget.
Voidstone has the low blast resistance of Netherrack, but it will never drop anything if destroyed by an explosion.
It can also not be destroyed by the Enderdragon or the Mjalnis Dragon.
It looks much like stone, but far darker and with a slight teal tint.