Julien Navas, of Paris, found the diamond while visiting the Murfreesboro, Arkansas park earlier in January. The diamond was sitting on the surface in the park’s 37.5-acre search area, according to a statement from Arkansas State Parks.
Mr Navas may have been aided by the weather; the region received more than an inch of rain just a few days before his visit. The muddy conditions may have helped to uncover the previously buried diamond, according to USA Today.
On the day of his discovery, Mr Navas rented a diamond-hunting kit from the park and began searching for the precious minerals.
"I got to the park around nine o'clock and started to dig," Mr Navas said. "That is back-breaking work so by the afternoon I was mainly looking on top of the ground for anything that stood out."
During his search he scooped up a few minerals he thought looked interesting and, when he'd had enough digging in the mud, he took his findings to the park's Diamond Discovery Centre.
It was there he learned that he'd found something special — a brown diamond.
The park's press statement described the diamond as rounded, similar to a marble, and approximately the size of a gumdrop candy.
Mr Navas said he planned to name his diamond after his fiance, Carine.
"I am so happy! All I can think about is telling my fiancee what I found," he said.
He reportedly plans to have the stone cut into two separate rocks, one for his fiance and one for his daughter. Mr Navas said he hopes to make a return visit to the park with his daughter when she is a little older.
Mr Navas joins three other lucky visitors who have found diamonds at the park this year, according to officials. However, his is notable for being the largest diamond discovered at the park since 2020, and the eighth-largest found since the the park opened in 1972.
In 2020, visitor Kevin Kinard found a 9.07-carat diamond in the park, which he named the Kinard Friendship Diamond. That diamond was only the second largest found at the park. In 1975, a visitor found the park's largest diamond to date — a 16.37-carat diamond later named the Amarillo Starlight.
Since the park opened in 1972, more than 75,000 diamonds have been discovered on its grounds.