Chemical element of metals. Cu comes from Cuprum, Fe comes from Ferrum, Ag from Argentum. The symbols were not followed by a period (full stop) as with abbreviations. Later chemical elements were also assigned unique chemical symbols, based on the name of the element, but not necessarily in English. For example, sodium has the chemical symbol 'Na' after the Latin "natrium". The same applies to "W" (wolfram) for tungsten, "Fe" (ferrum) for iron, "Hg" (hydrargyrum) for mercury, "Sn" (stannum) for tin, "K" (kalium) for potassium, "Au" (aurum) for gold, "Ag" (argentum) for silver, "Pb" (plumbum) for lead, "Cu" (cuprum) for copper, and
Britannia silver use by silversmiths from 1 June 1720, and thereafter Britannia silver has remained an optional standard for hallmarking in the United Kingdom and Ireland. Since the hallmarking changes of 1 January 1999, Britannia silver has been denoted by the millesimal fineness hallmark 958, with the symbol of Britannia being applied optionally. The silver bullion coins of the Royal Mint issued since 1997, known as "Britannias" for their reverse image, were minted in Britannia standard silver until 2012. Britannia silver should be distinguished from Britannia metal, a pewter-like alloy containing no silver. Britannia silver Britannia silver is an alloy of silver