Like many other mints, the Royal Mint issues bullion coins in precious metals, having much higher intrinsic value than their face value. The one ounce (1 oz) gold coins are denominated as One Hundred Pounds (£100).
The coins are legal tender but are not intended for circulation. They are targeted at bullion investors or collectors who appreciate the special editions as pieces of art. The coins are typically "one-year" types usually issued in parallel with smaller denominations with the same reverse designs.
This coin type is the tenth and final design from a series of ten coin designs known as the Queen's Beasts.
The Queen's Beasts are British coins issued by the Royal Mint in platinum, gold, and silver since 2016. Each of the coins in the series features a stylized version of one of the heraldic Queen's Beasts statues present at the coronation of Queen Elizabeth II representing her royal line of ancestry. It was announced that engraver Jody Clark will design the entire series; he is best known for also designing the Queen's Fifth definitive portrait, which is on the obverse of the coins - so he is in the rare position of having designed both sides.
The Queen's Beasts heraldic statues representing the genealogy of Queen Elizabeth II stood in front of the temporary western annexe to Westminster Abbey for the Queen's coronation in 1953. Each of The Queen's Beasts consists of an heraldic beast supporting a shield bearing a badge or arms of a family associated with the ancestry of Queen Elizabeth II. They were commissioned by the British Ministry of Works from sculptor James Woodford. The statues were uncoloured except for their shields at the coronation. They are now on display in the Canadian Museum of History. There are other statues of the Queen's Beasts, sometimes referred to as the King's Beasts, at Hampton Court Palace and Kew Gardens in London, and on the roof of St George's Chapel, Windsor Castle.
The Griffin of Edward III is an ancient mythical beast. It was considered a beneficent creature, signifying courage and strength combined with guardianship, vigilance, swiftness and keen vision. It was closely associated with King Edward III who engraved it on his private seal. The shield shows the Round Tower of Windsor Castle (where Edward III was born) with the Royal Standard flying from the turret, enclosed by two branches of oak surmounted by the royal crown - a motif also seen on the House of Windsor commemorative crown coin.
The Griffin of Edward III one ounce gold bullion coins were sold by the Royal Mint in individual plastic capsules, in Brilliant Uncirculated grade. | 
Search for United Kingdom: Gold Ounce 2017 Griffin of Edward III on eBay 