Hello, we have a new Hearthstone Heritage stove. We just cleaned it for the season. This material was sitting loose on top of the catalyst flap inside the top of the stove. It wasn't wrapped around anything. The only oddity we have had last season was two birds getting down into that pipe. Perhaps they knocked something loose. No other oddities. What is this material? Is it gasket ceramic wool, rock wool? Do we need to fix something before we can burn this season? It is a brand new stove installed last December. Thank you. - the wife.