The IX monogram or XI monogram is a type of early Christianmonogram looking like the spokes of a wheel, sometimes within a circle.[1]
The IX monogram is formed by the combination of the letter "I" or Iota for Iesous (Ιησους, Jesus in Greek) and "X" or Chi for Christos (Χριστος, Christ in Greek). The spokes can also be standalone, without the circle. These monograms can often be found as ancient burial inscriptions.[2][3]
Webber, Frederick Roth (1938). Church Symbolism: An Explanation of the more Important Symbols of the Old and New Testament, the Primitive, the Mediaeval and the Modern Church (2nd ed.).