If you have ever watched antiques roadshow (I'm pretty sure that is all of us who are old enough to remember when there were only 4 TV channels) you might have seen the experts looking at these little marks inside jewellery or on silverware.
The first attempt at regulating the standard of precious metals was made by Henry III in 1238, and most of the elements of modern hallmarking were in place by the 15th century. The Leopards head mark (see below) has been used since 1300.
A hallmark is legally required if you are selling over a gram of gold, half a gram of platinum or just over seven grams of silver. Each piece must be submitted to the Assay Office for testing, and they add a series of marks, as outlined below.
The mark is made up of 5 elements.
1: A makers mark
Each registered maker has a different mark made up of some initials inside a shape. Mine is NAS inside an oval shape. Each combination of initials and shape must be unique to the specific maker.
2: A traditional fineness mark.
This tells you what precious metal the piece is made of.
3: A millesimal fineness mark.
This gives you the percentage of the precious metal, so 925 means 92.5% which is the proportion of pure silver in sterling silver. A mark guarantees that the piece includes at least that quantity of the metal. The assay office test each piece they receive before applying the marks.
4: An assay office mark.
This identifies the office which marks the piece.
5: A date letter.
This tells you the year the piece was marked in.