GRAND RAPIDS, Mich. (AP) — A Michigan man curious about a rock he'd used for decades as a doorstop now knows its secret: it's a meteorite worth $100,000.

In fact, the nearly 23-pound hunk of iron and nickel is the sixth largest meteorite found in Michigan, according to the Smithsonian Museum and Central Michigan University.

David Mazurek said he took his doorstop to the university for examination after seeing reports in January of meteorite pieces selling for thousands of dollars.

"I said, 'Wait a minute. I wonder how much mine is worth,'" Mazurek said.

University Geology Professor Mona Sirbes...