Luke Lindoe prospected Montana and Idaho for clays during the 1970s. He found an amazing variety of fireclays, earthenwares and stonewares. Every color, texture, plasticity. For each he made test bars to fire at different temperatures. Our M2 and Troy clays originated from this work. We just found these bars, but do not have Luke's shrinkage and porosity data, so are measuring them now. He code-numbered each and stamped them with four-inch marks. So we can derive the total fired shrinkages and measure the porosities. We can tell a lot about the plasticity of each by the nature of the cut lines. The texture also is obvious. Now we just need to start searching Luke's map archives to find out where all of these are.