Behind the altar at the Basilica di San Marco, the exquisite Pala d'Oro is a gold, enamel and jewel-encrusted altarpiece (measuring 384cm by 212cm) made in Constantinople for Doge Pietro Orseolo I in 976. It was enriched and reworked in Constantinople in 1105, enlarged by Venetian goldsmiths in 1209 and reset in the 14th century. Among the almost 2000 stones that adorn it are 526 pearls, 320 emeralds, rubies, amethysts, sapphires, jasper, topaz and coralline.