This is a 36" tall prop Celtic Cross, created from poster board and gesso for a 3-dimensional effect. It simulates the appearance of stone while being lightweight enough to hang on a wall.
The design motifs used are spirals for the center and basketweave and knotwork for the arms.
The central design was slightly modified from the historical one by the addition of triquetra knots at the outside end of each spiral. It is not known if portions of these crosses were painted in period times, but I decided to go ahead and do that with colors matching pigments found in the 9th-century Irish monastic work called the Book of Kells.