You probably thought the mystery of the desert was “The Thing” along I-10 between Wilcox and Benson, but you would be wrong. The real mystery of the desert is “what in the heck did the Salado use for a white slip on Pinto, Gila and Tonto polychrome”?
Most of the stuff you read (POTTERY AND PIGMENTS IN ARIZONA: SALADO POLYCHROME) says that it was a kaolin type clay, but I doubt the people that write these things have ever attempted to duplicate Salado pottery. Experience has taught me that in an oxidizing firing the vegetable paint used by the Salado on a kaolin white will burn out leaving you with either gray or nothing at all. The Thornburgs have made some exceptional Salado reproductions, they use a powdered stone (not clay) from north of Phoenix that they believe to be volcanic ash. While this provides outstanding results, it has always bothered me that this type of volcanic ash outcrops are rare to non-existent in southern Arizona, I have a hard time imagining the Salado of this area traveling hundreds of miles to get their slip.
I was reading a book on the life of Maria Martinez a few weeks ago and may have found the answer. It said that the pueblos that use Bentonite Clay use vegetable based paint and those with Kaolin based clay have to use mineral based paint or the vegetable will fire out. Wow, there’s the answer, Bentonite clay is composed of weathered volcanic ash, and volcanic ash is what the Thornburgs have successfully used, there must be something about the porosity of volcanic ash that locks the paint in and doesn’t allow it to be burned out.
I have a couple of ideas I plan to try. One is to mix ground up volcanic ash with my white, kaolin based clay and see how that works. The other is that I know of a clay source about 4 miles from where I’ll be able to drive, on Sacaton Wash in the San Pedro Valley that I believe may be Bentonite clay, I am going to give that a try mixed with my kaolin white.
Tags: Clay, Gila Polychrome, Salado
Posted in: Pottery
