Privy marks are of particular interest to numismatists (def: coin collectors or students of money and exchange) but if your stash of precious metals expands into the realm of coinage, it is a subject worthy of this read on Goldbroker.com.
First, it is important to understand the mintmark. This is the mint’s engraving on a coin of a symbol, usually a letter, to indicate the mint at which the product was manufactured. In America, that is D for Denver, P for Philadelphia, S for San Francisco, and W for the West Point Mint. All coins, however, do not bear a mint mark; indeed, most coins from the Philadelphia Mint do not.
The privy mark goes beyond this location descriptor to the unique nature of the coin itself — its mintage. This means the same mint will produce coins with different, special privy marks. The practice is not at all common in the USA but it is standard procedure in many other countries (notably Canada and Australia) as a way to increase design and marketing values, and collector interest … and, therefore, monetary value.
Privy marks usually leave the single-letter method behind for the use of an attractive symbol such as an animal or other meaningful signification. The Royal Canadian Mint (RCM) is especially adept in this technique with its Silver Maple Leaf (SML) coin. Let’s take a closer look at an interesting example.
RCM featured a Mark V tank as a privy mark on one Silver Maple Leaf as part of its commemorations of the 100th anniversary of World War I. This was the first British heavy tank to require only one man to steer it, freeing up the gearsmen to fire weapons. 11 Mark V tanks survive, among them Number 9591 which was employed by Company A of the US 301st Heavy Tank Battalion in the attack on the Hindenburg Line on September 27, 1918 when it was hit by a two-inch shell. It was repaired and sent to the USA, where it is now in the collection of the National Armor and Cavalry Museum in Fort Benning, Georgia.
That whole story is told in the privy mark of one silver coin, so you can understand its value to a collector or an individual with personal or historical interest. To a coin dealer, the object probably represents standard price, in accordance with its precious metal content. At auction, the ask probably rises with the limit of its mintage and the sentiments attached to the story described above.
Is the additional premium attached to a coin with a privy mark worth it? That is entirely up to you, but privy marks come with some sort of symbolism and may indicate the uniqueness of a specific mintage.