Recent content by JOHT

I want to expose the hole decoratively to store wood for the fire in the other room. I don't intend for it to become a working fireplace.

I have discovered this in my fireplace behind an air vent. It is extremely hard to chip out and seems to be sealed in. There is no airflow up the chimney. If I keep trying to remove it, could damage my chimney breast? Does anybody know what it is? Thank you JOHL