This first picture is of the crunchy type creosote. It forms in my single wall pipe between the stove and the chimney (also in the stove sometimes). I don't think it's too dangerous, since it seems to be burnt already. It's kind of like cinders. It crunches and shatters, and cleans easily from the pipe. http://img.photobucket.com/albums/v604/quads/creo-crunchy.jpg
The second picture is of a paper-like stuff. It doesn't seem too flammable either. It forms inside the main part of the chimney and is almost like black, brittle paper. It mostly flutters to the bottom all by itself. Almost self-cleaning. http://img.photobucket.com/albums/v604/quads/creo-paper.jpg
The third picture is the bad stuff. It's what chimney fires are made of. I usually only get it in the top 6-12" inches of the chimney (you can see where it ends in the picture, at the weird wave-like creosote ring down below). It's almost like glass, but not as brittle. Adheres quite well to the chimney and requires a little scrubbing to get rid of it. Black, but often has a brownish tint. When you hear of creosote dripping out of a pipe, or creeping through bricks and into the wall, this is the stuff. http://img.photobucket.com/albums/v604/quads/creo-bad.jpg
The second picture is of a paper-like stuff. It doesn't seem too flammable either. It forms inside the main part of the chimney and is almost like black, brittle paper. It mostly flutters to the bottom all by itself. Almost self-cleaning. http://img.photobucket.com/albums/v604/quads/creo-paper.jpg
The third picture is the bad stuff. It's what chimney fires are made of. I usually only get it in the top 6-12" inches of the chimney (you can see where it ends in the picture, at the weird wave-like creosote ring down below). It's almost like glass, but not as brittle. Adheres quite well to the chimney and requires a little scrubbing to get rid of it. Black, but often has a brownish tint. When you hear of creosote dripping out of a pipe, or creeping through bricks and into the wall, this is the stuff. http://img.photobucket.com/albums/v604/quads/creo-bad.jpg