The Royal Mint has just produced the largest coin in its 1,100-year history to commemorate Queen Elizabeth II's historic 70-year reign.

>About the size of a small pizza, the one-of-a-kind Platinum Jubilee coin is made of .999 gold and weighs an astonishing 15 kilograms (33.1 pounds). The coin carries a denomination of £15,000, but the value of the precious metal alone is £776,595 ( $982,000).

Instead of being struck between two dies like a standard coin, this 220-millimeter-wide collectible was cut into a solid gold ingot by a high-speed precision milling machine before the processes of burnishing, polishing and frosting were carried out by hand to highlight key design elements. The process took nearly 400 hours of refinement using state-of-the-art engraving and laser technology.

A private UK collector commissioned the coin, which features a bespoke commemorative design that had been personally approved by The Queen, according to The Royal Mint.

“As the largest UK coin to date, the scale and diameter of the piece has allowed us to push the boundaries of minting to produce an exceptional level of relief and detail," said Paul Morgan, Technical Manager at The Royal Mint. "It is a true testament to the expertise and skills of our in-house design and production teams, and their ability to collaborate with the finest artists. The combination of traditional craftsmanship and modern technology has produced a truly one-of-a-kind piece of art.”

The private collector has been a long-standing customer of The Royal Mint and an enthusiastic investor in coins marking moments throughout The Queen’s reign.

"The latest and greatest in my collection is the Platinum Jubilee coin, designed by John Bergdahl and brought to life in 15 kilograms of solid gold," the collector said in a statement. "The beautiful design stands apart as a fitting tribute to Her Majesty’s service to our nation and the craftsmanship is simply breathtaking, ensuring a once-in-a-lifetime moment will live on in history on a UK coin.”

The reverse side depicts a crowned EIIR cypher surrounded by roses, daffodils, thistles and shamrocks, representing the United Kingdom. It also includes a symbolic privy mark of the St. Edward’s Crown worn during Elizabeth's coronation in 1953, positioned above the number "70," in recognition of Her Majesty’s momentous celebration.

On the obverse side of the coin, a special commemorative design depicting The Queen on horseback is engraved on the precious metal.

The Royal Mint has told the story of The Queen’s reign on UK coins since her accession to the throne in 1952, including five definitive portraits of Her Majesty.

Credit: Image courtesy of The Royal Mint.