When some vacationers visit public parks, they like to take something away with them as a memento. An arrowhead, for instance. Perhaps the imprint of a small fossil in a rock. Bob Wehle is one of these people. The Ripon, Wis., resident helped himself to a souvenir from his trip earlier this month ... and made headlines in the process. Wehle, you see, was in Crater of Diamonds State Park near Murfreesboro, Ark., which bills itself as "the world's only diamond site where you can keep what you find, regardless of value ." More than 25,000 glittering jewels have been carried home by tourists over the years. But few have been more impressive than the 5.47-carat prize that caught Wehle's eye. For starters, it's yellow in color and, so far, no one has found a single flaw in it. Park superintendent Tom Solarz told news agencies, "At first glance, it makes you think of lemon drop candy." It's the second biggest found in the park this year, but the larger one is brown and contains imperfections . OK, so how much is Wehle's memento worth? Well, Solarz and his staff aren't in the business of estimating that. But it's said to be identical in quality to a smaller one found there late last winter that gemologists have valued as high as $60,000.