Set of 6 mid century pop 1960s glazed earthenware cups

Very interesting set of 6 simple and spectacular pottery glazed earthenware coffee cups. Coated with a deep and soft black silver glaze, lined with a sensational klein blue, and the thick handle at an acute angle to animate the rather low and wide modernist form. No signs of use. Height 5cm. Diameter 6cm. Irresistible.