A man visiting the Crater of Diamonds State Park in Arkansas, found a diamond he plans to use for an engagement ring.Christian Liden, 26, has spent five years panning for gold in Washington, where he lives. As soon as he had gathered enough gold to make a ring, he headed to Arkansas in hopes of finding the perfect gem.Liden's big find came on his third day at the park."I saw it shining as soon as I turned the screen over and immediately knew it was a diamond," Liden said. "I was shaking so bad, I asked my buddy to grab it out of the gravel for me!"Park staff measured the large yellow diamond as measuring 2.20 carats.That's the largest found in the park since October.Liden isn't done with his engagement ring just yet. Next, he's headed to Nevada to mine for opals.The Crater of Diamonds State Park is one of the only places in the world that allows the public to search for real diamonds.