Purple Clay from the Wilds

For the last several blog posts I have been writing about the slow expulsion of allergens from my environment and the hunt for replacement items. This has been temporarity interrupted by my coming in to about one hundred pounds of locally mined South Carolina Clay. Processing this has taken up a significant portion of my time this week but the work has yielded exciting results. The raw clay, mined from the Congaree area, was found in striations of unusual colors; white, orange, buff, pink and purple. I had heard about the purple clay and begged an archaeologist friend for a sample from an excavation. I received a number of samples to experiment with. The orange and white clay was fairly pure and strained rather easily, if not always expeditiously. The purple and pink clay was another matter. Those colors were quite sandy and took a while to force through a colander. But, oh what remarkable colors the pinks and purples were! I took a picture of the purple clay drying on a plaster bat with purple pansies as a backdrop for color comparison (photo at right). The purple clay reminds me of the color used in some of the yixing ware produced in China, which makes me eager to see how this fires. The completely processed wild clay, in all of the color permutations, is shown above.

Should anyone reading this wish to try their hands at processing "found" clay I’ve outlined a few steps here:

1. Test the clay for plasticity by rolling a coil and bending it. If it cracks in many places it is too "short" to use.

2. If desired, sort the clay into component colors if it is mixed. (I did this with most of my found clay until I got tired of sorting and threw the remainder into a mixed bin and homogenized it).

3. Wild clay can be made stronger by the addition of volcanic ash. To make it more plastic add ball clay.

4. The wild clay should be divided into smaller pieces (preferably while still moist so as not to created dust) and soaked under water for a few days to a week.

5. The soaked clay should be made into a thin slurry by kneading with hands under water or by using a drill fitted with a paint mixer. If a small amount of clay is being processed, then it can be run through a blender.

6. The clay slurry should then be forced through a fine mesh colander (if there is a small supply) to remove debris, rocks, and coarse sand. If processing a large supply then it might be better to use a sheet of wire mesh screen fixed onto a wooden frame.

7. Strain into a plastic bucket or bin underneath the wire mesh. I sometimes use a stiff paint brush to force the clay through the mesh.

8. The slurry should then be allowed to settle in the bucket for a few days to allow the water to rise to the surface, where it can be siphoned off. I find a turkey baster very useful for this.

9. The thickened slurry should then be spread out on a plaster bat to dry.

10. Roll up the clay when sufficiently dry and wedge.