I've been making an underground road across my map from the spawn point to the dungeon, but I've been wondering what I should do with the stacks Ebonstone I picked up on my way through the corruption. Anything I've read has indicated the using it as a building material might not be a good idea. so, should I just purify it all? Or is there something else I can do/make with it?
You shouldn't use it as a building material because the presence of a lot of Ebonstone causes the sky and music transition seen in the Corruption, and allows Corrupted enemies to spawn.
What you could do with it:
As of patch 1.1, there are also a few more "real" uses: