Why are these blocks unbreakable? [duplicate]

Possible Duplicate:
How can I break the corrupted rock?

I'm in the corruption, and I noticed that the rock here is indestructible. Why?

The block type I'm facing can't be destroyed

That is ebonstone and it can only be broken with higher tier pickaxes.

From your screenshot, it looks like you have either an iron pickaxe or a silver pickaxe, neither of which are strong enough to destroy the ebonstone.

It is possible to destroy before you obtain the higher tier pickaxes using one of these methods:

• Dynamite
  • You can find dynamite in chests, or buy it from the Demolitionist if you have managed to get him to move in yet
• Purification powder
  • You can buy this from the Dryad if you have managed to get her to move in yet; after using the powder on the ebonstone, you will be able to mine the stone normally with your current pickaxe