The image of the crucifix of San Damiano miraculously spoke to Saint Francis "Go repair my Church, which as you see is falling completely in ruin". At first he set about repairing the physical churches but ultimately led to the founding of the Franciscan Order. The style of the crucifix that is used to represent this was first created in the 12th Century. Instead of showing Jesus in the traditional crucifiction image with nails, it is more a represntation of God supporting the cross to suggest the nobility and gentleness of eternal life, rather than the brutal reality of death.
The cross of San Damiano church itself is very distinctive in its design and was fully painted with images of other saints and people related to Christ's crucifiction. These images carry through in the design of the San Damiano jewelry.