This is a blend of minerals that closely simulates Barnard (Blackbird) Clay, a widely used clay that contains iron and manganese. Barnard clay has been used as a source of iron in dark firing glazes. It has a low plasticity and a high shrinkage rate. because it is a clay, it suspends very nicely in slurries it is added to. This is incredibly messy and will stain everything it comes into contact with!
Information from the Digitalfire Ceramic Materials Database
