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.
Yin and yang < *"ʔəm" compares with Burmese "ʔum" "overcast; cloudy", Adi "muk-jum" "shade", and Lepcha "so'yǔm" "shade"; and is probably cognate with Chinese "àn" < *"ʔə̂mʔ" "dim; gloomy" and "qīn" < *"khəm" "blanket" "Yang" < *"laŋ" compares with Lepcha "a-lóŋ" "reflecting light", Burmese "laŋ" "be bright" and "ə-laŋ" "light"; and is perhaps cognate with Chinese "chāng" < *"k-hlaŋ" "prosperous; bright"; "bǐng" < *"braŋʔ" "bright"; "liàng" < "*raŋh" "(pale) light"; "lǎng" < "raŋʔ" "brilliant light"; "míng" < "mraŋ" "bright, become light, enlighten". Schuessler surmises that those items either are areal words (cf. Tai "plaŋ" "bright") or belong to an Austroasiatic word family (cf.