The metal is analysed to determine its metal type and purity and is then marked with a series of symbols, known as its hallmark. It’s extremely challenging to know the type of gemstones that a ring is made of by simply looking at the metal or even touching it. Platinum, silver and gold are the most adored metals for making jewelry worldwide. However, jewels made of these are not solely made of one pure precious metal but rather a combination of metals known as metal alloys.

Metal alloys (combining several precious metals) is a method used to make the metals more durable, enhance their strength, and sometimes to enhance the colour. Hallmarking is a technique that involves putting marks on metal pieces to authenticate the amount of precious metal contained in them.


Hallmarking can be dated back to the 13th century when official stamps consisting of a series of marks started being made on jewelry of gold, platinum or silver stones. In France and England, the governments appointed assayers whose duty was to examine and authenticate the purity and fineness of jewelry that was officially being traded. Although the methods and requirements for hallmarking have changed over the years, the principal behind it remains the same and it has become a legal requirement in most states.


The first step in hallmarking is to take a sample of the metal from a scratch, which is then analysed in a lab, and the type and purity of the metal are determined. Multiple symbols are then imprinted inside the precious metal. Punch marks in gold or platinum rings are therefore a guarantee that the metal pieces have undergone testing, and the metal purity and legal standards have been met.

There are many types of hallmarks, but the following are the most prevalent ones:


The sponsor’s mark is the registered mark of the company that requires the item to be hallmarked. This mark is unique for everyone and is formed of the initials of the person or company. In our case, our sponsor’s mark is a MOH.


This mark identifies what metal the item is crafted from.


This mark is used to show the percentage of the original metal used in the creation of a jewelry or a ring. This mark indicates what quality the metal is, also known as its fineness. The numerical format was introduced in 1999 and expresses the precious metal content of the item, in parts per thousand.



This mark tells you which Assay Office tested and hallmarked the item. The London Assay Office uses the image of a leopard’s head as its stamp, recognised throughout the industry as the renowned home of precious metal hallmarking.


Every country has its own rules governing the trade of metal items. While in some countries the markings made by the manufacturer are sufficient, in others it’s compulsory that extra marks are made by an independent unit. In the UK, for instance, hallmarking is only imposed on precious metal items from a specific weight. In Switzerland, only watches must be hallmarked and hallmarking for all other items is optional. There are no specific standardised hallmarking rules in Italy. In 1972, a group of European nations signed the Vienna Convention on the Control of the Fineness and Hallmarking of Precious Metal Objects. Since then, it has been termed as the Common Control Mark (CCM) and countries that signed the convention agree that metals with this mark can be freely traded without the need for further testing.

To conclude, it is important that both sellers and buyers understand the need for hallmarking for their own interest and also to ascertain that they get value for their money. If you are purchasing an item that doesn’t have a hallmark or you don’t trust the hallmark, you should have an expert jeweller test it for you.

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