What is Hallmarking?

 If you have a piece of gold, platinum, palladium, or silver jewellery, no doubt you’ve noticed a series of marks somewhere on it. These symbols are known as hallmarks and are mandatory on all pieces of jewellery made with precious metals in the UK. But what is hallmarking? Hallmarking refers to the mark applied to pieces of precious of precious metals, which asserts that the purity and fineness of the metal has been independently and tested and verified.

What is the Hallmarking Process?

 The hallmarking process is comprised of several steps, which comes under the term ‘assaying’. Assaying is the analysis of an article’s composition. This is primarily carried out using X-ray Fluoresence Spectroscopy (XRF), which is an entirely non-intrusive technique. Occasionally, other methods will be used, including removing the surface layer, touch stone testing, cupellation, silver titration, and platinum and palladium testing, which uses the ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy). For traditional methods, a physical sample must be taken from the piece by scraping/drawing.

Of these methods, there are three which are particularly important. Gold cupellation, which is a 2000 year old process, involves the separation of the pure gold portion of the alloy from the base metals in order to calculate the gold content. Silver titration is the analysis of pure silver within an alloy, which involves the dissolution of the silver alloy in various chemicals. Lastly, touch testing, which dates from 500 BC, involves rubbing the piece on a touchstone, leaving a thin streak of material on the stone. These are then subjected to chemical tests to determine the fineness.

Why do we Hallmark?

 As with any product, it’s quite easy to be misled about what we’re actually buying. It is difficult to ascertain how much precious metal is contained in items of jewellery by looking or touching it. There are certainly some people who would take advantage of this fact and try to pass off jewellery with low amounts of precious metal content as one with high amounts. Using a hallmark ensures that the exact purity of an item has been independently tested.

In essence, it is simply a form of consumer protection, with rising importance as more and more jewellery is being sold online, providing more opportunities to fool consumers.

What is the Hallmarking Act?

 Hallmarking is considered to be the oldest form of consumer protection in the UK and has a long history. In 1300, The Goldsmiths’ Company Assay Office began testing and hallmarking precious metals. Since then, hallmarking has progressed to the Hallmarking Act of 1973, which requires that all items sold in the United Kingdom and that claim to be made of gold, silver, platinum, or palladium must have a legally recognised hallmark.

What Marks Comprise a Hallmark?

 A complete hallmark consists of three compulsory marks:

 Sponsor’s Mark: The registered mark of the company that submitted the article for hallmarking/testing.

Millesimal Fineness Mark: Indicates the precious metal and its content of the piece, expressed in parts per thousand.

 Assay Office Mark: Indicates which Assay Office tested and hallmarked the piece.

In addition to compulsory marks, there are three optional marks that might be applied to the piece as well.

 Date Letter: Indicates the year the item was hallmarked. It is signified by a letter, which changes on January 1st every year.

Traditional Fineness Symbol: A symbol that depicts the metal that is used.

Convention Mark: This mark is used for pieces made in countries with which the UK has an international treaty, encouraging the cross-border trading of precious metals. If an item has this mark, it need not be hallmarked for sale in the UK. The convention hallmark shows the fineness of the metal, with scales surrounding the number.

What is an Assay Office?

 An Assay Office is a site that tests the purity of precious metals. If the item passes these tests, the Assay Office marks it with the appropriate hallmark.

The Different Assay Offices

There are only four Assay Offices in the UK, each with their own unique symbols.

London: The mark for the London Assay Office is famously the head of a leopard.

Edinburgh: Edinburgh’s Assay Office uses the mark of a castle.

Birmingham: Birmingham’s Assay Office’s mark is an anchor.

Sheffield: The mark used by the Sheffield Assay Office is a flower.

Fairtrade Hallmark

 As well as applying the above marks, the UK Assay Offices are responsible for applying a Fairtrade mark to any jewellery that uses Fairtrade Gold. The Fairtrade mark is a miniaturised version of the internationally recognised fairtrade symbol. The addition of this mark was only a recent development, having been added from 2011.

Fairmined Hallmark

 In addition to Fairtrade gold, Fairmined gold is also hallmarked. This hallmark was also used for the first time in 2011, with the first item of jewellery marked to be made from Fairtrade Fairmined gold being a ring by Sam Love. Since then, many ethical wedding rings and other pieces of jewellery have been hallmarked by this symbol.