It is one of the most beautiful chapels of the Basilica. On the altar, there is the triptych, signed by Bartolomeo Vivarini from Murano (1474), which represents St. Mark, in the act of blessing, sitting on a Renaissance throne capped by four angels, two of which are sitting on a step and playing a lute and a ‘viella’. The throne in white marble is decorated with fine Lombardesque arabesques from the late Renaissance period. Two pillars adorn the throne and, above the capitals which do not have an architrave, there is an arch which acts as a rest for three angels who bear a swag, garnished with fruit and foliage, which hangs to either side in a symmetrical curve. On the left, St. John the Baptist and St. Jerome, and, on the right, St. Nicholas and St. Peter. The entirety of the part carved in golden wood with pinnacles and foliage, bearing the prophets Jeremiah and Jonah, which surround the Madonna, is in Florid Gothic style and acts as the frame through which the sacred scene can be seen, outlined by velvet red oranges which appear darker and lighter depending on how the light falls. The darker shades of red, however, combine perfectly with the gold of the wooden frame. The altar-piece reveals the best of the artist’s deftness and skill especially in painting the saints, depicted with precision and yet in gold and bright, rich colours which recall the splendour of the glasses and enamels produced in Murano, his birth-place.
The holy water stoup was donated to the church by Daniele Giustiniani. The stoup was converted into a christening font by placing on top a marvellous marble statue of St. John the Baptist, one of the most inspired works of Jacopo Tatti known as Sansovino. Experts state that the work was commenced between 1534-1537 and was completed before 1540. On the marble is the inscription: “Iacobus Sansovinus Florentinus faciebat”. Mariacher states: “The refined taste for detail and technical perfection is strikingly clear to the naked eye, not only in the human body but also in the natural elements such as the tree trunk, the woolly skin covering the Saint and the details etched with extreme finesse”.