You never know what something's worth, unless it's worthless.

 And if they say it's 'priceless' or 'invaluable',

 you're equally screwed...

A priceless Roman mosaic that once decorated a ship used by the emperor Caligula was used for almost 50 years as a coffee table in an apartment in New York City. Dario Del Bufalo, an Italian expert on ancient stone and marble, described how he found the mosaic in an interview with CBS’s 60 Minutes on Sunday.

In New York in 2013, Del Bufalo gave a lecture and signed copies of his book, Porphyry, about the reddish-purple rock much used by Roman emperors. The book included a picture of the long-lost mosaic, which once formed part of a floor on one of two vast “party ships” commissioned by Caligula to float on a lake near Rome and sunk when the emperor was killed.

The mosaic and other antiquities were recovered from the lake in the 1930s and housed in a lakeside museum. In 1944, as the Nazis retreated from Italy, the ships and many other treasures were burned.

Nearly 70 years after that, as he signed copies of his book, Del Bufalo overheard a man and a woman say the woman had the mosaic they were looking at on the page.

“There was a lady with a young guy with a strange hat that came to the table,” Del Bufalo told CBS. “And he told her, ‘What a beautiful book. Oh, Helen, look, that’s your mosaic.’ And she said, ‘Yeah, that’s my mosaic.’” Del Bufalo tracked down the young man, who confirmed that “Helen” had the mosaic in her apartment in Manhattan.

She was Helen Fioratti, an art dealer and gallery owner. According to an interview she gave the New York Times in 2017, she and her husband, an Italian journalist, bought the mosaic from an Italian noble family in the 1960s. When it arrived in New York, the couple turned it into a coffee table. “It was an innocent purchase,” Fioratti told the Times. “It was our favorite thing and we had it for 45 years.”