A simple Chinese vase made over 800 years ago and unveiled in Hong Kong Monday is expected to fetch HK$60 million ($7.7 million) when it goes under the hammer next month, Sotheby’s said.

The plain octagonal piece, tinted a milky blue, was created during the Southern Song Dynasty and is just 20 centimetres (eight inches) tall.

Despite its simplicity it represents the most coveted art of the period, Sotheby’s said, since it is part of a rare collection crafted for the imperial court, known as “guan yao” or “official ware”.

The vase is from the same collection as a Chinese porcelain bowl which fetched nearly $27 million at a Sotheby’s sale in April 2012 (below). That price was a record for Song Dynasty ceramics.

The Southern Song Dynasty vase is part of Sotheby’s Hong Kong Chinese Works of Art spring sale, which starts on April 7.