Celtics size 12mmhole size 2x8mm. The Triade, Triskle or Tripal spiral. - This is an ancient Celtic symbol related to earthly life, the afterlife, and reincarnation. it is drawn in one continuous line, suggesting a fluid movement of time. Triades are one of the most common elements of Celtic art. They also evoke the universal concept of the domains of material existence- earth, water, and sky; body, mind and spirit; and the eternally spiraling cycles of time.