To be able to get the pick strength required, yes. You could just blow your way through ebonstone with dynamite if you needed to.
Wish you could craft dynamite. I've only found 2 sticks which I already used to break 1 shadow orb.
Also, totally spent 80% of my life-savings to buy a minishark, killed the Eye of Chutulu or whatever the forget it's called, and I now am waiting for the dryad to spawn. Purification powder, shadow orbs, eater o' worlds, nightmare pick, underworld, hellstone, obsidian skull, conquer all. :D