VTG Clay City Pottery Large Mixing Blue Bowl Scalloped USA Stonewear Bread 12. This bowl is about 12″ across the top and about 6.25″ tall. It is marked Clay City Pottery USA on the bottom. Blue glaze with a stripe on the top and around the lip that is unglazed. This bowl is heavy just over 7 1/2 pounds! And has a gorgeous scallop design.