The Carolina Gold Rush, the first gold rush in the United States, followed the discovery of a large gold nugget in North Carolina in 1799, by a 12-year-old boy named Conrad Reed. He spotted the nugget while playing in Meadow Creek on his family's farm in Cabarrus County, North Carolina.[2]:11 [3] Conrad took the 17 lb gold nugget home to show his father. However, gold was not commonly seen in their community and the value of the nugget was not understood. The nugget was used as a door stop in the family's home for several years. In 1802, Conrad's father, John Reed, showed the rock to a jeweler, who recognized it as gold and offered to buy it. Reed, still unaware of the real value of his "doorstop," sold it to the jeweler for $3.50 (approximately one week's pay for a farm laborer at that time).
From Wikipedia - https://en.wikipedia.org/wiki/Carolina_Gold_Rush
To this day, most jewelers you ask what the value of an item is will respond with "How much do you want?"