After her husband said she would not have any luck gem hunting, a Tennessee woman discovered a 1.30-carat diamond in Arkansas' Crater of Diamonds State Park - the world's only publicly operated diamond site where regardless of their value, the public is allowed to search and keep any gems found.

Melissa Lacey of Knoxville said, "I wasn't expecting to find anything and was just picking up pretty rocks."

Her first thought on seeing it was that is was "a piece of dirty quartz" but the park staff identified it as a diamond.

The AP reports that the diamond that was the size of a piece of candy corn, is the largest diamond ever discovered in the U.S. It was unearthed here in 1924 and named the Uncle Sam. It weighed 40.23 carats.

A freshly dug trench was opened to the public on Saturday and was opened to the public but Lacey found her diamond there Thursday.