A piece of the Italian sarcophagus of early Christian apostle St. Paul will be displayed May 20 at the Cathedral of St. Paul, the Archdiocese of St. Paul and Minneapolis announced Thursday.

The relic, brought from Rome in March by cathedral rector the Rev. Joseph Johnson, will serve as an object of veneration for devout Roman Catholics. It consists of a stone removed from the tomb, which lies beneath the Basilica of St. Paul Outside-the-Walls in Rome, Johnson said.

In June 2009, Vatican archaeologists drilled a hole into the sarcophagus and inserted a probe to remove a sample of its contents, Cathedral of St. Paul spokeswoman Carolyn Will said in a news release. The contents included purple fabric, red incense, chalk and protein substances. Bone fragments were sent for carbon-14 testing, which concluded that they came from someone who lived around the first and second centuries A.D.

"This would seem to confirm the unanimous and undisputed tradition which claims that these are the mortal remains of St. Paul," Pope Benedict said at the time. "All of this fills our hearts with profound emotion."

The sarcophagus stone will be on view from 7 a.m. to 7 p.m. May 20, at the cathedral, 729 Selby Av. Ritual veneration will occur outside that day's mass times at 8 a.m., 10 a.m., noon and 5 p.m. Until a more permanent location for the relic is secured, it will be the only public viewing, cathedral officials said.

The cathedral, which in 2009 was designated as the U.S. national shrine of St. Paul, now becomes an even more significant pilgrimage site, Johnson said.

"Every religious tradition has a notion of pilgrimage, and for Catholics, the tombs of Saints Peter and Paul are major sites," he said. "Most people never make it to Italy, so this further enhances our designation as a national shrine. ... Seeing this gives people a sense of closeness to the apostle Paul, who was the first to spread the Christian message."

Pamela Miller • 612-673-4290