Warded Stone Edit
They are (almost*) literally indestructable to anyone but the player who placed them. Even IC2 Nukes cannot destroy these blocks - when a set of 9 nukes was detonated inside a chamber composed of one-block-thick walls of Warded Stone, no terrain was damaged at all. They will not absorb the radiation effect, however, so bear this in mind.
Other players have been known to encase your impervious base with their own impervious blocks, preventing you from leaving your base. The Portable Hole is NOT able to tunnel through these blocks.
It also seems that you can't place Warded Stone with a Wand of Equal Trade, the game mechanics considering it as something/one else, and not , placing the stone.
Required Research is . This unlocks with the