<p>Graniteware has a porcelain enamel surface over a steel core body. The steel core is an excellent heat conductor and gives an even heat distribution for faster cooking times. The glass-like enamel surface does not interact with foods and cleans up easily with warm soapy water. Black. Originally founded in 1871, Granite Ware is the oldest cookware manufacturer in the U. S., famous for producing Porcelain on Steel cookware.</p>