A mysterious Han blue artifact could be a piece of ancient Chinese art or a scientific curiosity.
Han blue is a synthetic pigment that was developed in China and used from the Western Zhou period (1045–771 BC) until the end of the Han dynasty (circa 220 AD).
It has the chemical formula BaCuSi 4 O 10 and a layered structure with silicate forming the framework.
It is more stable than Han purple, another synthetic pigment that has a similar color but a different formula and structure.
Han blue was used to create blue and purple colors in paintings, ceramics, and other artworks.
Some examples of Han blue artifacts are:
A mural from an Eastern Han tomb near Luoyang, Henan, showing a pair of Liubo players, a board game popular in ancient China.
A mural of a Western Han tomb in Luoyang City, depicting a landscape with mountains, rivers, trees, and buildings.
A cloisonné vase from the Ming dynasty, decorated with flowers and birds in blue and other colors.
Han blue is also interesting for its exotic properties and applications to superconductivity and quantum computing research.
In 2006, scientists showed that Han blue "loses a dimension" under suitable conditions when it enters a new state, as a Bose-Einstein Condensate.
This means that the electrons in the pigment behave as if they are in a two-dimensional plane, instead of a three-dimensional space.