The Greek cross with four arms of equal length is pre-Christian, and in paganism, represented the four elements: earth, air, fire and water. It has been used for centuries in Christian art.
The image below is an engraving of a cross on a headstone located at Golden Gate National Cemetery in San Bruno, California.
CROSS FIVE FOLD
When five Greek crosses are displayed together, they represent the five wounds inflicted on Christ during the crucifixion (nails in the hands and feet and a spear in his side). This cross was popular in the Crusader era.
A circle superimposed on a Greek cross is representative of the crown of thorns placed on Christ’s head during the crucifixion.