(CNN) — An Arkansas man who picked up what he thought was a piece of glass at a state park says he later learned his jelly bean-sized find was something much more valuable: It was a 4.87-carat diamond.

Jerry Evans visited Crater of Diamonds State Park in Murfreesboro, Arkansas, for the first time with his girlfriend last spring, he told park officials.

Evans says about 10 minutes after they arrived, he spotted what looked like glass a few feet away on top of a plowed ridge, according to a news release.

Though he pocketed the pyramid-shaped find, he wasn’t sure if it was a diamond, Evans said in the release.

“It was so clear. I really didn’t know,” Evans said. “We were picking up everything thinking it was a diamond.”

Crater of Diamonds, which became a state park in 1972, is known as a source of diamonds from their original volcanic source, according to park officials.

After later returning home about 250 miles away in Lepanto, Arkansas, Evans says he pondered whether the small object could be something more than glass, so he sent it to the Gemological Institute of America for help identifying it.

The nonprofit California-based institute specializes in gem and jewelry research and education, according to its website.

Evans heard back from the institute a few weeks later, when they informed him he had found a near-colorless diamond, according to the release.

“When they called and told me it was real, I was tickled to death!” he said.

Evans then contacted the park about the discovery. His diamond became the largest one registered at the park since Labor Day of 2020, when Kevin Kinard of Maumelle, Arkansas, found a 9.07-carat brown diamond there, according to park officials.

“While I get many emails from people wanting me to identify something they’ve found here, to my recollection, this is the first time someone has contacted me after they’ve had a diamond identified by the GIA,” Waymon Cox, assistant park superintendent at Crater of Diamonds State Park, said in the release.

Park visitors find an average of one to two diamonds there daily, and 798 diamonds totaling more than 125 carats have been registered at the park in 2023, according to the release.

More than 75,000 diamonds have been discovered at Crater of Diamonds since the first diamonds were found in the area of Pike County, where the park is located, in the early 1900s, according to the park’s website.