Bust of a Saint in a mandorla

The saint represented in this relief may be Saint John the Evangelist, as he is represented beardless and holding the Holy Scriptures. Saint John the Evangelist is said to have written many parts of the Bible, that is why he is often represented writting or holding it. The peculiar oval shape of the medallion in which he is sculpted is called a 'mandorle', which is Italian for 'almond'. This shape in fact corresponds to a mathematical shape, the vesica piscis, which first appeared in Euclid's writings. It has then been used by Christian art, for illuminated manuscripts for example.