I found some bentonite/kaolinite purple colored clay along the local river bed. So I dug some, slaked it, sieved through a 40 mesh. The clay shrank 16% when fired and melted at cone 5 into a "dog poo like pile" of brown yuk. Not very good for building. But I made a terra sig slip from it and applied it to greenware - Laguna half and half. It did not do anything in the bisque firing, but at cone 5 it created a chocolate brown semigloss Albany-like glaze which breaks over the ridges to a lighter tan. It also has flecks of yellow to green.
I want to use this as a base glaze/slip but would love suggestions from the audiance, experts, critics, etc. on how to tweak this into a good product. When dipped thin the glaze is a buck skin semi transparent color.