This recent discovery was previously unknown to the numismatic community
Authenticated and certified by NGC (and approved by CAC), this 1852 gold dollar pattern (Judd 138) is the only known U.S. pattern or coin that was gold plated (gilt) by the United States Mint and then overstruck. It was originally a silver Seated Liberty dime that was cut down (trimmed to size), perforated (creating a hole in the center), gold plated, and then struck by the 1852 gold $1 pattern dies.
This piece should not be confused with coins or patterns that were struck first and then gilded either inside the Mint or by collectors after they were released. Careful examination of the cut-down edge, the striations around the center hole and the overall surfaces confirm that it was gold plated first, then struck as a pattern.
Expert Fred Weinberg, PCGS authenticator for mint errors, has handled many patterns, experimental strikes, overstrikes and unique pieces. He was also one of a handful of experts that authenticated all five known 1913 Liberty Head Nickels at the 2003 ANA. In 1974, while at Numismatics Ltd., he purchased most of the Kosoff Judd Pattern Collection from Abe Kosoff. Fred said that there were a few mint errors and experimental strikes, but nothing that compared to this pattern.
“It’s the first U.S. Mint gold plated pattern that has been certified and authenticated by either PCGS or NGC, that was struck over another U.S. coin,” Weinberg stated.
Gold plating is the process of applying a thin layer of gold to the surface of the coin, usually through a process called electroplating. Gilding is a process of applying a fine gold powder or gold leaf to the surface of the struck coin, without the use of electric current.
The 1852 Gold Dollars were struck in gold, silver, copper, copper-nickel, nickel and brass. There are two known Judd #147 gold dollar patterns that were gilded after they were struck – certified PCGS MS-62 and PCGS PR-65, respectively.
The probably unique Judd #138 clearly demonstrates that the Mint was experimenting with manufacturing methods to strike these gold dollar patterns. Different metals were used as blank planchets. They were perforated, and a few were struck on silver dimes instead of blanks. This new coin is important because it proves that the U.S. Mint gold plated a struck coin first, prior to using it to strike a pattern.