Mosan Reliquary Cross
The cross on which Christ is crucified in this reliquary is green, which alludes to the tree of life. This is framed by a background of colorful stars. Both of these elements point to the Crucifixion as a cosmological metaphor for the universe and as a moral instrument, enforced by the inscriptions of the virtues. These values are also reflected in the writings of many medieval theologians. The imagery and inscriptions used in this reliquary cross show that reliquaries reinforce important religious virtues for people of the faith who engage with these relics.
(1) https://art.thewalters.org/detail/21139/reliquary-cross-2/