Pièce 1 once d'argent NGC MS-69 (PL) Britannia 2014 | La Monnaie royale

When a sharp-eyed coin dealer spotted a major mistake on one of the world's most popular silver coins early this year, the international press went berserk.

Headline after headline appeared in print and online.

But the coverage wasn't just limited to the coin press!

Mainstream news outlets on both sides of the Atlantic carried the amazing story:

A Britannia mule coin had just been discovered for the first time!

What is a "Mule" coin?

Well, just as a mule is the offspring of a horse and a donkey, a mule coin is one struck from two dies which were never intended to be used together.

For example, the heads side of a quarter with the tails side of a half dollar.

This kind of dramatic mule error creates HUGE public attention!

Number one on the list of the top 100 coin errors among collectors is a mule coin struck with a Washington Quarter on one side and a Sacagawea Dollar on the other side!

To err is human - but government mints have very strict quality controls designed to catch mistakes before they leave the mint.

Mule coins errors very, very rarely make it into the public's hands.

Need proof? In over 200 years of U.S. Mint history, only four confirmed mule errors are known.

And all four U.S. errors are on base metal coins, not on silver.

The world has never seen a large silver dollar sized mule.

Until now!

To err is human - to err in SILVER is divine!

Britain's Royal Mint has been striking British coins for over 1,000 years—and they rarely make mule errors either.

But as the Royal Mint began shipping their newest annual Silver Britannia coins for 2014, an eagle-eyed dealer noticed a problem - one that would become the first recorded mule error for such a major annual silver coin series!

You see, the rim of the Silver Britannia coin traditionally features a decorative edge which is "crenelated".

This means that it features a notched design that looks much like the ramparts along the top of a castle, or the teeth of a large gear.

One side of the 2014 Silver Britannia bears this distinctive edge.

But the obverse of the coin—which features the royal portrait of Queen Elizabeth II—was discovered to have a smooth edge instead.

The British Britannia is one of the world's most popular annual issue silver dollar sized coins.

To suddenly have a mule error variety appear on the market triggered an avalanche of interest - and demand!

Collectors go crazy!

As the news broke and collectors realized what a historic "first ever" this Silver Britannia Mule represented, demand for this coin exploded!

British collectors - desperate to get their hands on one - have paid as much as $499.95 for an ungraded example of this coin.

That's not surprising, of course, since mule coins are discovered so rarely, and the Silver Britannia Mule is the first for a major, large diameter silver world coin.

Each of these coins have been certified and graded by one of the world's leading third-party authentication services, Numismatic Guaranty Corporation (NGC).

NGC authenticated each coin and awarded them the near-perfect collector grade of Prooflike 69 (PL69).

ABOUT THE ROYAL MINT

The Royal Mint is internationally recognized as one of the most prestigious and highly acclaimed mints in the world with a history of over 1100 years. The Royal Mint produces original coin collections, investment grade bullion, as well as currency for over 60 countries including the United Kingdom. Popular series from The Royal Mint include the Britannia products, Queen’s Beast, British Music Legends, and Myths and Legends.