Britannia coins are British bullion coins issued by the Royal Mint in gold since 1987 and in silver since 1997. The original Britannia silver coins contain one troy ounce (1 oz) of silver and have a face value of £2.
Silver Britannias are also issued in fractional sizes of one-half, one-quarter, one-tenth, 1/20th and 1/40th of a troy ounce and with face values of £1, 50p, 20p, 10p and 5p respectively (that is, the quarter ounce silver piece is officially denominated as 50 pence). There is also a five-ounce coin of face value £10.
After 2013, the proof versions of the coin feature a different design each year, while the bullion versions of the coin - such as this one - have the classic, or "definitive" Standing Britannia reverse design.
The Royal Mint says about the coin;
Britannia has long featured on British coins and has evolved through the ages to reflect the nation she represents. In 1987, a stunning incarnation of Britannia was created by sculptor Philip Nathan for a new bullion coin. His Britannia was bold and beautiful and presented with carefully chosen symbols to reflect the nation’s values - a shield for protection, an olive branch for peace and a trident for her maritime links. The internationally recognised design is so highly regarded that only The Royal Mint is able to strike genuine Britannia coins featuring Philip Nathan’s interpretation of the icon. His design is as beautiful as ever and features on this quarter-ounce coin, struck in 999 fine silver and enhanced by The Royal Mint’s bullion finish. | 
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