A new pope gets a new ring, the Ring of the Fisherman also known as the Piscatory Ring.
Although the conclave is still locked away in contemplation in the Sistine Chapel master goldsmith Claudio Franchi, the man who made the ring for Benedict is in a unique position to explain the symbolism:
“According to ancient ritual, described in history going back to the 13th Century, the ring is used as a seal to stamp official documents. After a serving pope dies the ring is destroyed with a silver hammer by the Camerlengo in front of the Cardinals in order to avoid forgery. For Benedict the ring was a symbol not a seal.”