This stemcup is made of a very thin pottery, and is completely hollow. It is very light weight, and the pottery is carbonized due to reduction firing in the kiln. These cups were made on a fast turning wheel, and are unique in the history of ceramics worldwide. This example is 21cm high, and has a few restorations to the cup. A very similar piece is in the Smithsonian museum, object object S2012.9.201 The Longshan culture is placed in Shandong province, These pieces are dated approximately between 2500-2000 bC.