Charlotte, N.C. — Nearly 50 years after a mysterious spear-shaped stone was found 30 miles east of Charlotte, N.C., archaeologists have a theory that likely dates the “unusual artifact” to between 3,000 and 1,000 BC.

The stone, discovered in 1973 in Union County, was clearly too big and heavy to qualify as one of the ubiquitous arrowheads found in agricultural fields across the state.

It’s 7.2 inches long, 2 inches tall and nearly an inch and a half wide, the N.C. Office of State Archaeology posted on Facebook.

So what is it?

David Cranford of the Office of State Archaeology believes what the landowner found is an ancient tool: An adze (or adz) used for smoothing and trimming wood.

“It is unclear how old this object is, but if it was made during the time that many of the grooved axes were being made and used, it would likely date to the Late Archaic period (3000-1000 BC),” Cranford said in a post that accompanied a 3D model of the stone.

The tool “could have been used prehistorically to make wooden bowls, dugout canoes, or other wooden objects,” state officials posted.

Cranford, an assistant state archaeologist, says an examination of the stone suggests a handle would have been attached for use in “a technique called pecking and grinding.”

“Unlike a grooved ax, the tapered end of this tool would have been oriented perpendicular to the handle and was not ground smooth,” state officials posted on Facebook. “Note the edge damage on the tapered end.”

The exact spot where the stone was found was not revealed, but it was near Monroe on land owned Ken Batson, Cranford posted.

Much of the area along the state’s border with South Carolina was home to the Catawba Nation, a federally recognized indigenous people now based in York County. An indigenous group known as the Lumbee lives farther east along the state line, in Robeson County, N.C.

The discovery of the suspected adze is not unlike the July 2019 unearthing of a stone in Newton Grove that had a face carved in it, McClatchy News reported earlier this year.

It was 22 inches long and nearly 17 inches wide, the newspaper said. State officials have not yet published an analysis of the stone face, including how old it might be.