Han Purple

Han Purple, also called Chinese Blue, is a pigment that has been used in China for over 2,000 years.^[1] Chinese alchemists first synthesized Han Purple from barium copper silicates (Molecular formula: BaCuSi₂O₆ ).

Han Purple is a color that is close to electric indigo. It is a purple in the sense that the term is used in colloquial English, i.e., it is a color between red and blue; however, it is not a purple in the sense that the term is used in color theory, i.e. a non-spectral color between red and violet on the line of purples on the CIE chromaticity diagram. Perhaps the most accurate designation for the color would be to call it Han Indigo, although it could also be regarded as a bright shade of ultramarine (thinking of ultramarine as a color and not a pigment).

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Molecular structure, origin, and use

Han Purple or Chinese Blue is a type of artificial pigment with colors blue or purple found in China between 500 B.C. and 220 A.D.. It was used in the decoration of the Xian Terracotta Army. The compound consists of barium, copper, silicon and oxygen with chemical formula BaCuSi₂O₆ and is related to Egyptian Blue with formula CaCuSi₂O₆ (calcium and not barium) and it is believed by some that the Chinese variety has Egyptian roots. In a 2007 study on the other hand it is suggested that Chinese Blue is in fact a Chinese invention ^{[2] [3]}. The study identified traces of lead in fragments of Terracotta Army pigment. Lead has never been found in Egyptian Blue but has been used in China as a flux in the production of glass (reducing melting temperature). With Chinese technology available in 500 B.C. barium (as barite or witherite) added a jade-like quality to the glass, in high demand by Taoist monks. The study concludes that the Chinese Blue is a glassmaking spin-off.

Han purple in human culture

Chinese culture

• The terracotta warriors in Xian (which are from the Ch'in Dynasty) were dyed with Han purple.
• Han purple was used in large imperial projects and pottery during the Han Dynasty.

References

1. ^ Raiders Of The Lost Dimension--Understanding The Quantum Mechanics Of The Universe (ScienceDaily June 2, 2006):
2. ^ Influence of Taoism on the invention of the purple pigment used on the Qin terracotta warriors Journal of Archaeological Science, Volume 34, Issue 11, November 2007, Pages 1878-1883 Z. Liu, A. Mehta, N. Tamura, D. Pickard, B. Rong, T. Zhou and P. Pianetta doi:10.1016/j.jas.2007.01.005
3. ^ Oeroud Alchemistisch success in Azie Hendrik Spiering NRC Handelsblad 4 October 2007

See also

• Egyptian Blue
• List of colors
• Maya Blue
• Prussian Blue