When our altars were placed against a wall and priests said Mass with their backs facing the congregation, vestments would be decorated with religious symbolism on the backs of the vestments and sometimes at the center of altar frontals. Today the symbols are often featured on the front of chasubles. One very common motif was the vesica pisces. The triqueta is but a triple vesica pisces, used to indicate the Holy Trinity.
The shape of the vesica pisces is derived from the intersection of two circles, the Pythagorean “measure of the fish” that was a mystical symbol of the intersection of the world of the divine with the world of matter and the beginning of creation. Sometimes called the “Jesus Fish”. it literally means “fish bladder. The custom of early Christians to communicate by drawing a portion of it in the dust was carried over from the practice of the ancient Pythagoreans, who discovered the shape’s unique properties and made it an important part of their teachings. Within the vesica can be found the triangle, the tetrad, the square, the pentacle, and many more polygons, making the vesica truly symbolic. Many church textiles, architectural motifs and church coat of arms and insignia are enclosed in the vesica as well as aureoles which sometimes are seen enclosing saints or angels. The shape is sometimes called a mandorla.
Aureole around Our Lady of Guadalupe