Taijitu seen in Tripilja culture in Ukraine, displayed in the Ukraine pavilion at the Expo 2010 in Shanghai, China. Also, the interlocking design is found in artifacts of the European Iron Age. While this design appears to become a standard ornamental motif in Iron-Age Celtic culture by the 3rd century BC, found on a wide variety of artifacts, it is not clear what symbolic value was attached to it. Unlike the Chinese symbol, the Celtic yin-yang lack the element of mutual penetration, and the two halves are not always portrayed in different colors. Comparable designs are also found in Etruscan art.
Taijitu the "yin and yang symbol", itself popularly called "taijitu", represents the second of these five parts of the diagram. The term "taijitu" in modern Chinese is commonly used to mean the simple "divided circle" form (), but it may refer to any of several schematic diagrams that contain at least one circle with an inner pattern of symmetry representing yin and yang. While the concept of yin and yang dates to Chinese antiquity, the interest in "diagrams" (圖 "tú") is an intellectual fashion of Neo-Confucianism during the Song period (11th century), and it declined again in the Ming period, by