Page "Alpha and Omega" Paragraph 11

Therefore the letters Alpha and Omega in juxtaposition are often used as a Christian visual symbol ( see examples ).

The letters were shown hanging from the arms of the cross in Early Christian art, and some crux gemmata, jeweled crosses in precious metal, have formed letters hanging in this way, called pendilia.

In fact, despite always being in Greek, the letters became more common in Western than Eastern Orthodox Christian art.

They are often shown to the left and right of Christ's head, sometimes within his halo, where they take the place of the christogram used in Orthodox art.