This is a Qingbai box measuring 87mm in diameter. It was found in a shipwreck in the Indonesian sea, most likely the Jepara wreck.The dating according to the shipwreck data is late Northern Song, 11th-12th centuries, from the Dehua kilns.The dating of the wreck is under debate, so to be more sure a broader dating Song/Yuan dynasty is more safe.
The bottom and the lid show a different color of glaze. According to a Gotheborg.com colleague these parts were separately fired in the kiln. The temperatures were different according to the placement of the piece in the kiln. The lids and bottoms of the boxes were pieced together in a later stage, after firing.