Last week I posted a question about inspection my chimney for creosote. That day, I cleaned out the contents of my chimney access door (in the basement) figuring the stuff in there was leftover debris from the stove installation when they created a new opening in the chimney on the first floor. So today I inspected it again and found this: (The quarter is for size reference. My chimney is, unfortunately, not producing small change.) I'm always careful to burn hot fires with as little smoke as possible. Is this normal or should I be concerned?