WOBURN, Mass. -- At Gerrity Stone in Woburn, they know a lot about rocks. But they can't identify the one that punched a hole through their roof the other day.

NewsCenter 5's Kelley Tuthill reported that experts are examining the object, trying to determine exactly what it is.

"No one around here has ever seen anything like this. A real mystery," said Gerrity's Alan Weiner.

One would expect to find granite and marble at the stone warehouse, but workers were surprised to find the unusually heavy object on the floor.

"Then we looked up at the ceiling and, 'Oh my God. It fell through the ceiling,'" Weiner said.

For answers, Weiner headed to Sky And Telescope in Cambridge where J. Kelly Beatty examined the object.

"I'm suspicious that it's rusty and it shouldn't be rusty," Beatty said.

Beatty did some tests on the object, which weighs about 1.24 pounds.

"This is interesting. It's clearly got some metal in it. The magnet does attract," Beatty said.

Beatty said there is a chance the object could be a meteorite.

"A third of me says 'yes,' but two-thirds says 'no,'" Beatty said.

Beatty was intrigued enough by the object to take photos and e-mail them to an expert at Harvard University. Beatty said meteorites are rare.

"The only one known meteorite to have fallen in Massachusetts and that was in Northampton in 1963. That was iron, as this appears to be," Beatty said.

Meteorite or not, it's a mystery how the object fell from a warehouse ceiling.

If the object is a meteorite, experts said it could be worth a couple of thousand dollars.