It's called "basement rock," but it's unlike anything you'll find in the deepest basement.
It is a dense piece of reddish sandstone that last saw the light of day when Kentucky was a very different place.
It is 6 inches high and 4 inches in diameter, and it is thought to be a billion years old.
The "8030" painted on its side offers a hint of its origin: It came from 8,030 feet below the surface of Hancock County.
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The rock was brought up from a test well dug to help scientists find out if carbon dioxide can be stored deep below the surface instead of being spewed into air.
At 8,126 feet, the well is one of the deepest ever dug in Kentucky.
Such Kentucky basement rock is so rare that there might be only 650 or so pounds that have ever been brought to the surface, including the 450 pounds from the Hancock County well.
Rick Bowersox, who is studying the rock at the Kentucky Geological Survey at the University of Kentucky, notes that by comparison, 840 pounds of rock were brought back from the moon.
The Hancock County rock is expensive — it cost about $5,000 a foot to bring 30 feet of it up from the bottom of the well.
Bowersox is studying whether it is suitable rock to store carbon dioxide.
So far, it appears too dense for that, he said, although scientists say that shallower layers will work just fine.
He's also looking for clues to how the rock and the North American continent were formed.
In addition, he might be able to get information from the rock about volcanic activity, and perhaps even long-ago climate conditions.
Based on research in Ohio, the rock probably was formed by the erosion of a granite mountain range somewhere north of what is now Kentucky. It was carried to its longtime resting spot by a series of streams and shallow rivers.
It is highly unlikely that any fossils will be found in the rock, Bowersox said. There were no life forms on the Earth's surface that long ago, he said, although there were some simple things in the oceans.
All the erosion that occurs now is affected by life forms, Bowersox said. The forces that turned a granite mountain into reddish Kentucky sandstone were purely mechanical and chemical, not biological.