(IDEX Online) - A visitor to a state park in Arkansas, USA, discovered the "piece of glass" he picked up was actually a 4.87-carat diamond.Jerry Evans and his girlfriend were visiting the Crater of Diamonds State Park, near Murfreesboro, which charges day trippers $10 a day to sift the soil - and lets them keep any gems they find. "I thought it might be a piece of glass, it was so clear. I really didn't know," Evans said. "We were picking up everything thinking it was a diamond."He sent his find to the GIA, and they confirmed it was a near-colorless 4.87-carat diamond."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," said assistant park superintendent Waymon Cox. "I'm glad that Mr. Evans was able to bring his historic diamond back to the park to have it officially registered."Visitors to the park search a 37-acre field, the eroded surface of a volcanic crater, for a variety of rocks, minerals, and gemstones - and keep whatever they find.During 2023, a total of 798 diamonds have been recovered, with a combined weight of more than 125 carats.Pics courtesy Crater of Diamonds State Park