Until 1998, a Hallmark consisted of four COMPULSORY MARKS. Since 1998 the date letter has become optional but the other three symbols remain compulsory. The symbols give the following information:
• who made the article
• what is its guaranteed standard of fineness
• the Assay Office at which the article was tested and marked
• the year in which the article was tested and marked
Sponsor's Mark (formerly known as the Maker's mark)
This shows the person or company responsible for sending the article to the Assay Office. The sponsor may be the manufacturer, retailer, importer, for example.
These show the standard of fineness - the purity of the precious metal,
in parts per thousand.
E.g The background shape shows the metal (gold).The figure shows the article consists of 750 parts of gold by weight to 250 parts of other metals - 75% gold. This is equal to 18 carats (18 parts in every 24), the traditional way of describing gold purity.
Current Gold standards
Current Platinum Standards
Current Silver Standards
Assay Office Mark
There are now only four British Assay Offices in existence, but there have been more in the past.
Hallmarking was originally introduced in 1300 by a Statute of Edward I and is one of the earliest forms of consumer protection.
Hallmarking is necessary because when jewellery and silverware are manufactured, precious metals are not used in their pure form, as they are too soft. Gold, Silver, and Platinum are always alloyed with copper or other metals to create an alloy that is more suitable to the requirements of the jeweler. Such an alloy needs to be strong, workable, yet still attractive.
Owing to the high value of gold, platinum and silver, there are significant profits to be gained by reducing the precious metal content of an alloy at the manufacturing stage. Base metal articles plated with a thin coat of gold or silver look the same as articles made wholly of precious metal, at least until the plating wears, and even an expert cannot determine the quality or standard of precious metal items by eye or touch alone.
With volume manufacturing, enormous profits can be made from even a small reduction in the amount of precious metal used. Without compulsory independent testing there is huge potential for deception and fraud.
The UK Hallmarking system has offered valuable protection for over 700 years. Compulsory Hallmarking protects all parties; the public who receive a guarantee of quality, the manufacturer who is given quality control and protection from dishonest competitors at a very low cost, and the retailer who avoids the near impossible task of checking standards on all his goods.
For Example Hallmarking Gold
1) Gold is assayed using a free refining method called cupellation. The legal standards for Gold in the UK are:
2) Every parcel received is now immediately bar-coded, and this means that it is traceable at a moment’s notice wherever it is in the chain of processes to which every item is subjected.
3) After being unpacked, weighed, checked, and compare to the clients details in the preparation department, the goods are passed on to the next stage.
4) Samplers work alongside a conveyer belt which takes parcel from Goods in up to the Marketing Department.
5) Before the actual sampling takes place, acids are apply to detect sub-standard parts, plating or excessive use of solder.
6) During sampling, small amount of metal are very carefully scrape or cut from the article to produce laboratory-sized samples of less then0.25 gram.
7) After sampling the articles are transported by an automated spiral conveyer to the next floor; this eliminates much manual work with out of date lifts that need to be loaded by hand. The actual samples remain on the ground floor and are passed to the Balance Room where they are weighed to an accuracy of one hundred thousandth of a gram on highly sensitive balances.
8) The samples are then wrapped in lied foil together with a pre-determined quantity of silver. This assists with removal of the base metals when the samples are subjected to the heat of the furnace.
9) The samples are then sent on the furnace room, where they are placed on special porous blocks, called cupels, for fining. In the furnace, the cupels are heated to 1100 degrees Celsius. At this temperature, the cupels absorb the lead and any based metals as oxides. The sample forms a bead, consisting of pure gold and silver only, and when cooled these are flattened and rolled into spirals called cornets. The cornets are boiled in nitric acid to dissolve out the silver and finally, annealed to complete the process, living fine gold.
10) Comparing the weight of this fine gold with the weight of the original sample gives the degree of purity. This comparison is automatically calculated by computers link to the balances.
11) If the samples assayed achieve the required gold content, they are passed and sent on to the Marking Department for the hallmarks to be applied. Hallmarks are applied to articles by press. By hand-marking or by the latest technique laser-marking.
12) The presses we use are either hydraulic or hand-operated. The method of marking and the type of press employed is governed by the quantity and nature of the articles and the size of hallmark to be applied large and awkward-shaped articles are still marked by hand.