The bone fragments were presented like rings in a jewelry box in a display case that was placed next to the altar. The service when these relics were made public was part of a Mass commemorating of a yearlong celebration of Christian faith.
The nine pieces of bone were found in the necropolis under St. Peter's Basilica. While no other pope declared that the fragments really belonged to Apostle Peter, Pope Paul the VI said in 1968 that these were indentified to belong to St. Peter in a way that is considered convincing.
Some archaeologists dispute the finding. Some top Vatican officials are not 100% certain that these are really St. Peter's bone fragments. But with all this doubt there is also a lot of hope. After all it doesn't really matter if one day someone will come and prove that the bones don't really belong to St. Peter because the Christians that have prayed at St. Peter's tomb will continue to do so in the upcoming millennia too.