Triquetra silver with emerald

Triquetra — the ancient ornamental and sacred symbol of the peoples of Central and Northern Europe.

In the stone and bronze age Triqueter was one of the symbols of the motion of the Sun, embodying the main provisions of the luminaries (accordingly, at sunrise, Zenith and sunset).
There has been speculation about the connection of the symbol with moon phases and renewal of life.
The sign was very common among the Northern Nations of Europe — Celts, Frisians, and Scandinavians. In particular, the sign is present on Celtic crosses, where, it is said, symbolizes the triad and is a symbol of the sea God Manannan Mac LIR.
In Norse and Teutonic symbolism sign is associated with Thor.

Also, long before the advent of Christianity, Triquetra was borrowed by the Slavs and the personified triad of worlds (yav, prav, NAV), although there is likely more appropriate to draw a parallel to the solitary varieties of trikvetra, the symbol of Odin "will Valknut".

In the neopagan religion of Wicca Triquetra represents three aspects of the goddess (virgin goddess, mother goddess, and the wise old woman). Triquetra within a circle emphasizes the aspect of unity.

Triquetra as a symbol of the Trinity found in Christian symbolism called "Holy Trinity" and represents the three-dimensionality of space, time and space. These three aspects exist independently from one another, and yet they represent the one God. Later the Holy Trinity became the symbol of the Divine unity in three expressions — God the Father, God the Son (Jesus Christ) and God the Holy Spirit.
However, the understanding of trikvetra as a symbol of the Holy Trinity is not widely spread.

The symbol is much older than Christianity, it is closely associated with the characters "Valknut" and "Triskelion". Objects decorated with Triquetra, have been found in many parts of the old world.

In modern culture the symbol points to Norse or Celtic paganism.