This is a small cup, 7,5 x 4,5 cm. It is made from a very high fired stoneware and is thin potted. It has a high pitch when tapped, almost like porcelain. It is decorated with squigled lines from a little comb. I would say all these things point directly to the Warring States, although the shape is quite rare. The 250 years between 475 and 221 BC is called the Warring States Period because the region of the Zhou Dynasty was divided between 8 states. These states had frequent wars until 221 BC when Qin conquered them all.(chinahighlights.com) The W.S. produced some very interesting pottery, and this one fits in with my other pieces. Similar shape pieces, but glazed are dated as Spring and Autumn Period, as in Nanjing museum and the Shatzman collection.