Monroe salt works-Monroe,Maine -makers of salt glazed stone ware -which is earthenware fired in a kiln and as the temperature reaches 2500 degrees salt is thrown into the kiln and as the salt vitrifies- it forms an impenetrable coating on the piece-you can recognize stoneware by its tannish color and orange peel texture and feel of its finish -the company ceased operation in 2010 -always popular the prices continue to rise-these jumbo coffee mugs are done in their popular berry pattern