Fortunately, with the use of a single reference book, it is possible for even a complete novice to decipher the vast majority.Although there are many books on the market which can be used to help read hallmarks, the standard book of reference, used by dealers and collectors world wide is Bradbury's Book of Hallmarks.Marks indicate it is Britannia gauge silver made by (or for) Paul de Lamerie (taken to or) in London and dated 1732 (it could have been made a year or two earlier than 1732).
In Ireland, sterling silver is not less than 92.5% pure silver, the rest is alloy. Below are a few examples and a guide to reading antique Irish silver hallmarks, followed by photos of as many date letters as I could manage. As there are only 26 letters in the alphabet, they are reused, which each cycle slightly different to the preceding one.
The hallmark for sterling silver varies from nation to nation, often using distinctive historic symbols, although Dutch and UK Assay offices no longer strike their traditional hallmarks exclusively in their own territories and undertake assay in other countries using marks that are the same as those used domestically.
One of the most highly structured hallmarking systems in the world is that of the United Kingdom, (Scotland, England, Wales and Northern Ireland), and Ireland.
It is a form of consumer protection, whose origin goes back almost 1000 years.
There are so many different hallmarks found on British silver that to know all of them would be impossible.