To determine the coefficient of friction of a specific type of tile, you would need the assistance of a material testing laboratory or refer to the manufacturers specifications for the Pennyweight Schist tiles.
Coefficients of friction vary depending on the surface conditions, including the degree of roughness, moisture content, and other factors. Without specific information about the surface conditions and testing results of the Pennyweight Schist tiles, it is not possible to provide an accurate value for their coefficient of friction.