Time passed, and as we were working on the Prescott Wares section of this guide we were referencing the Northern Arizona Universities online guide to Southwestern pottery. Flipping through the pages, an article title caught my attention, "How to tell Tusayan White Ware Pottery from Asbestos Floor Tile". The article is very scientific, explaining temper examination, comparing the paint, actually refiring a chip of the "suspected" asbestos floor tile, and examining the surface carefully with a microscope. However, the difference is fairly easy to see once you know what you are looking at. Floor tiling had never crossed our mind in our study of the two questionable sherds but alas we found our answer.
The black lines on the floor tile is tar that is applied to the undersurface. These can look like black parallel lines similar to those seen on many prehistoric black-on-white pottery types. The thickness is about the same. Upon microscopic examination, sparse asbestos fibers can be seen. Asbestos floor tile is usually found at historic trash dumps, old trading posts, and along Route 66 tourist stops, but may occur in isolated finds.
We did not think that this was something that would come up as a question for the lay-person. In fact, until recently, we had not thought about these tile pieces for years. Just recently we were contacted to identify sherds being found on someones property. The location, Southeastern Arizona. The photographed pieces were emailed along with a note saying that the "sherds" are being found all around a very old "cement" ruin. It is because of this recent inquiry that we have decided to share these photographs. And no, there isn't enough asbestos in the floor tile to hurt you.
