The term “Britannia” has a couple of meanings in the metal refining industry. There is Britannia silver, a grade of silver purity and composition, and Britannia metal, which is a type of alloy.
Although the two forms of Britannia are very different in terms of value, they are both lustrous, silvery metals. Britannia metal is very similar to pewter. It’s an alloy containing 93% tin, 2% copper, and 5% antimony (a metal similar to lead). Pewter usually made of 85–99% tin, with the rest being a mixture of copper, antimony, bismuth and lead.
Britannia metal alloy is very smooth, which makes it a perfect base metal for electroplating and gilding. As a matter of fact, the Oscars presented at the Academy Awards are made of Britannia with gold plating. Britannia is also commonly used as the base metal for cutlery with silver gilded on top. However, it’s important not confuse this type of cutlery for other sets made of Britannia silver.
Britannia silver is a standard of purity first issued by British parliament in 1697. It contains 95.84% silver (the rest is usually copper). Britannia silver was meant to become the new metal-working standard of purity for special and artisanal projects – replacing sterling silver, which is 92.5% pure. Aside from artisanal work, Britannia silver is also used for the bullion coins produced by Britain’s Royal Mint.
To tell whether you have something made of Britannia metal or Britannia silver, check for a mark indicating millesimal fineness. Britannia silver should have a 958 mark, while Britannia metal will have a much lower (or non-existent) one.