Hallmark

A hallmark is an official marking made by a trusted party, usually an assay office, on items made of precious metals (platinum, gold and silver) that guarantees a certain purity of the metal. This should not be confused with a marking, often just a number such as 925, which is done voluntarily by the manufacturer, and unfortunately does not always reflect the true purity of the metal. A hallmark is only applied after the item has been assayed to determine its purity. Often the hallmark is made up of several elements including: the type of metal, the maker and the year of the marking.

Merriam-Webster also defines hallmark as "a distinguishing characteristic, trait, or feature (eg. the dramatic flourishes which are the hallmark of the trial lawyer -- Marion K. Sanders)".

History of hallmarking

Hallmarking may have begun as long ago as the sixth century AD. Byzantine silver from this time has a system of five marks which have not been completely deciphered.

Hallmarking is Europe's earliest form of consumer protection. Hallmarking probably started in France, the standard for silver being established in 1260, but the first town mark was established in 1275.

In 1300, King Edward I of England enacted a statute ordering that all silver articles must meet the Sterling silver standard (92.5% pure silver), and should be assayed by 'guardians of the craft', who would then mark the item with a leopard's head.

In 1327, King Edward III of England granted a charter to the Worshipful Company of Goldsmiths (more commonly known as the Goldsmiths' Company), marking the beginning of the Company's formal existence.

In 1355, individual maker marks were introduced in France, which was mirrored in England in 1363, adding accountability to the two systems.

In 1427, the date letter system was established in France, allowing the accurate dating of any hallmarked piece.

In 1478, the Assay Office was established in Goldsmiths' Hall. At this time, the date letter system was introduced in England.

In 1697, a higher standard of silver, known as the Britannia standard (95.8% silver) was made compulsory in England to protect the new coinage which was being melted down by silversmiths for the silver. The Sterling standard was restored in 1720.

In 1975, the 1973 Hallmarking Act was enacted, introducing Platinum marking. All four remaining assay offices finally adopted the same date letter sequences.

The latest changes in 1999 were made to the UK hallmarking system to bring the system closer into line with the European Union (EU).

International hallmarking has been plagued by difficulties, because even amongst countries which implement hallmarking, standards and enforcement varies considerably, making it difficult for one country to accept another's hallmarking as equivalent to its own.

List of countries with statutory independent hallmarking as of 2004

• Austria
• Belgium
• Cyprus
• Denmark
• Estonia
• Finland
• Germany
• Greece
• Hong Kong
• Italy
• Latvia
• Luxembourg
• Malaysia
• Malta
• Netherlands
• Norway
• Singapore
• Slovenia
• Sweden
• Switzerland
• United Kingdom
• Uzbekistan

Modern hallmarks

United Kingdom hallmarks

Pictured here are the assay office marks - from left to right, the leopard's head of London, the anchor of Birmingham, the Yorkshire rose of Sheffield, and the castle of Edinburgh.

As it now stands, the compusory part of the UK hallmark consists of the sponsor or maker's mark, the assay office mark, and the standard of fineness (in this case silver, 925 parts in 1000). These are shown in the top of the two example hallmarks. The bottom example shows the extra marks that can also be struck, the lion passant, indicating Sterling silver, the date mark (lowercase a for '2000'), and in this example, the 'Millennium mark', which was only available for the years 1999 and 2000. The bottom example bears the Yorkshire rose mark for the Sheffield Assay Office.

Vienna Convention hallmarks

Marking techniques

Punching

Traditionally, the hallmarks are 'struck' using steel punches. Punches are made in different sizes, suitable for tiny pieces of jewellery to large silver platters. Punches are made in straight shank or ring shank, the former for normal punching with a hammer, and the later used with a press to mark rings. The problem with traditional punching is that the process of punching displaces metal, causing some distortion of the article being marked. This means that re-finishing of the article is required after hallmarking. For this reason, and that off-cuts from sprues are often used for assay, many articles are sent unfinished to the assay office for assay and hallmarking.

Laser marking

A new method of marking using lasers is now available, which is especially valuable for delicate items and hollowware, which would be damaged or distorted by the punching process. Laser marking also means that finished articles do not need to be re-finished. Laser marking works by using high power lasers to evaporate material from the metal surface. Two methods exist, 2D and 3D laser marking. 2D laser marking burns the outline of the hallmarks into the object, while 3D laser marking better simulates the marks made by punching.