Shoes, clothing and furniture are the typical items donated to charities on a daily basis. But a 10,000-year-old mastodon tooth? Not so much.
John Timmer, an employee at the charity's warehouse, found the ancient artifact there in July when going through the day's donations.
"I picked it up and it looked like a tooth," Timmer, 52, told GoodMorningAmerica.com.
"The root was intact and it was cracked enough so you could see enamel," added Timmer, of Jenison, Mich. "It definitely looked like some sort of tooth. But I didn't really know what to do with it."
Therefore, he did what any unsuspecting employee would do and stowed it away in a cabinet in the warehouse.
"About a week went by and I called the museum to see if they had somebody that could tell us what this thing is," said Timmer.
Almost immediately, one of the Grand Rapids Public Museum's curators arrived to pick up the ancient artifacts, which included a tusk-like piece in addition to the tooth, to inspect what the charity had inherited from a mysterious donor.
"He said, 'Yeah, it's a mastodon tooth and it's probably about 10,000 years old," Timmer recalled.
The tooth, which was "quite heavy," according to Timmer, is roughly 10 inches long and about the size of a loaf of bread.
"And there was a sharper piece that looked like a tusk, possibly, and that one was probably a little bigger, about a foot long and maybe five inches wide," he said.
The mysterious part is that no one knows where the donation came from.
"We do pickups for donations all the time, mostly at people's estates if grandfather passed away and the family decides to donate their belongings to us," said Timmer. "But I suspect whoever donated it didn't know it was there."
But now, the mastodon pieces have found an appropriate home, being used as an educational tool for the museum.
"The fact it will be used for education purposes is the coolest thing," said Jay Starkey, the charity's director. "They're going to let the kids feel it, touch it and learn about it. How cool is that?"
And as for the monetary value of the pieces from the extinct, elephant-like species, Starkey said it didn't matter.
"It doesn't matter what the value was, because this educational value is priceless," he said.