According to a report from the San Francisco Chronicle, a gold nugget weighing more than six pounds sold Friday for $400,000 to an unnamed buyer. The California nugget went on display Thursday.

“Nuggets like this don’t come along every day,” David McCarthy, the nugget’s appraiser, told CNN. “I really didn’t believe that I would see a California nugget of this size unearthed during my lifetime.”

The Associated Press notes that during the Gold Rush prospectors unearthed large nuggets, such as a 54-pound chunk discovered in Butte County in 1859. However, this was the first time in many years that anyone has found a nugget weighing six pounds or more in the Golden State.

“Large California nuggets are incredibly rare and valuable,” said Donald Kagin, president of coin-distributor Kagin’s Inc., in a statement. “In 2010, a man contacted us claiming to have discovered a 98-ounce nugget on his property also in northern California. After auctioning the piece for $460,000, we were made aware that it was actually found in Australia where such giant nuggets are more common. We immediately refunded the buyer, paid his agent a commission, resold the piece as an Australian specimen to the second highest bidder for a lesser amount, retained our commission and paid the original consignor (who wanted to use the nugget sale to sell his property) the balance. Everyone was satisfied with the outcome, and we are excited about another opportunity to offer such an historically important gold nugget.”

The San Francisco Chronicle adds that even though the nugget has been sold, it will remain on display until the show ends Sunday.