Hallmarking
What is a Hallmark?
A hallmark is a set of marks applied to precious metals which has been independently tested and verified and conforms to all legal standards of purity and fineness.
The History of Hallmarking
The London Assay office in Goldsmiths' Hall is the oldest assaying office in the UK. It was founded in 1327 to regulate and test the quality of gold, silver and later on platinum (1975) and palladium (2010) articles. The word "hallmark" originates from the 15th century where London craftsmen were first required to bring their metal artefacts to Goldsmiths' Hall for assaying (testing) and marking.
Originally there were 12 assaying offices in the UK, now there are 4, London, Edinburgh, Birmingham and Sheffield.
The London mark for authentication is the leopard's head which was the King's mark introduced in the 1300's under the reign of Kind Edward I. The mark itself was taken from the three lions passant on the Royal Arms and a crown was added in 1478 to differentiate articles marked before this date. In 1822 the crown was dropped and the lion gradually transformed to a leopard.
In 1544 the Goldsmiths' Company adopted the King's mark as their town mark and the leopard's head is now recognised as the mark of the Assay Office London.
Anatomy of a Hallmark
The London hallmark is the Full UK hallmark consisting of 5 traditional marks:
1) Sponsor’s Mark (Maker’s Mark)
2) Traditional Fineness Symbol
3) Millesimal Fineness Mark
4) Assay Office
5) Date Letter Mark
A letter mark coinciding with the date of assay was first introduced in London in 1477. Originally it signified the Assay Master responsible for testing and marking the silver. The date letters were changed on the day that the Goldsmith's Guild wardens were elected, originally the feast day of Saint Dunstan, patron saint of gold and silversmiths (19 May) until the Restoration (1660) and 29 May thereafter.
The Hallmarking Act of 1973 brought the remaining 4 British Assay Offices (London, Birmingham, Sheffield and Edinburgh) into line with each other with the date letter now changing (from 1975) on 1 January each year.
An example of our Hallmark on a bespoke Alexandrite 9k gold ring.
UK Hallmarks
Hallmarking in the UK guarantees the standard of fineness and purity of silver, gold, platinum and palladium.
Symbols of a Full UK Hallmark
1) Sponsor's Mark (Maker's Mark)
Our registered mark for Freeform Jewellery.
2) Traditional Fineness Symbol
3) Millesimal Fineness Mark
This mark tells you how fine, or what quality, the metal is, as well as indicating the metal type. This numerical format was made compulsory in 1999 and shows the precious metal content of the article, expressed in parts per thousand. The piece is marked to the lowest standard of precious metal, so it guarantees that the quality of the whole article is no less than the fineness indicated. The shape of the surrounding shield indicates metal type.
4) Assay Office Mark
This mark tells you which Assay Office tested and hallmarked the article. The historic image of the leopard’s head, the town mark for London, and the mark of the Goldsmiths’ Company Assay Office, continues to be internationally recognised as the stamp of approval and guarantee of quality from the renowned home of hallmarking.
5) Date Letter Mark
A non-compulsory mark, the date letter changes annually on January 1st. The font, case, and shield shape all change so each can only indicate one specific year. All date punches are destroyed at the end of the year.
The Hallmarking Process
1) Testing the purity of the metal. This is called assaying.
2) Assaying is an ancient process. It has been used for metal authentication for over 2,500 years.
3) The Goldsmiths’ Company Assay Office has been assaying traditionally for nearly 700 years.
4) Today most assaying is done using a X-ray fluorescent (XRF) Spectrometer.
A) You place the item inside the machine and the item is exposed to an X-ray beam.
B) The X-ray causes the metal to release fluorescent energy.
C) The fluorescence is measured to show the exact quantity of each consistuent element.
5) The metal purity must meet or exceed the minimum standard required.
6) Occasionally, traditional methods are used which include touch stone testing, cuppelation, silver titration, and platinum and palladium testing using ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy)
