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.
Chinese sun and moon mirrors respond with fire: the pure essence of "yang". When placed before the moon—the ultimate "yin" 陰 phenomenon in the world—they respond with water: the pure essence of "yin". Thus mirrors offer the paradigm for "proper responsiveness": they reflect the true essence of the ultimate "yin" and "yang"—the alpha and omega of phenomena in early Chinese cosmology." (Carr and Ivanhoe 2000: 56) Erin Cline says the early Chinese attributed mirrors to have a mysterious power and great religious significance. The ceremonial bronze "fusui" 夫遂 and "yangsui" 陽燧 mirrors were seen as active, responsive objects because they could be used to produce