A $50 coin produced in 1855 by Kellogg & Co has sold at the top of Heritage Auctions' CSNS US Coin Signature Auction, held April 23-27 in Chicago.
The coin formed part of the Riverboat Collection of Territorial Gold, which housed some of the finest examples of coins made from gold discovered during America's gold rushes.
Described as "the most beautiful of all pioneer gold", it sold for $763,750.
When gold was first discovered in California, currency in the impromptu towns created to house migrant workers was measured in "pinches". However, this was clearly an uncertain means of measuring the gold, and many companies produced their own coins without the permission of the United States government.
Just 14 examples of the Kellogg $50 coin are known, and this is considered the finest. They are thought to be trial examples, as none were ever released into circulation.
The $763,750 price was matched by an 1849 $5 Pacific Company coin, graded AU58, which is the finest of only four certified examples.
An 1849 $10 coin produced by Mormons in the Great Salt Lake Valley also appeared, selling at $705,000. Fashioned from some of the earliest gold found during the California Gold Rush, the coin was produced for Brigham Young, an early leader of the church.
Paul Fraser Collectibles has some exceptional investment-grade coins for sale.