I am still perplexed by the behavior of the clay on the carved bits. It could be exterior crud. It could be a sign that this was not made of Yixing clay - in which case it's a prettily executed fake. I took some warm water and a nail brush to the outside of the pot yesterday after I dumped out the tea and it seemed to help some, so I am hopeful that it was just dirt and dust.

And the tea tasted just fine, so....