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British Hallmarks

The idea of this guide is to give you a comprehensive guide to buying British Assay Office marked jewellery. There are a couple of others online which are useful, but we're trying to give you as much information in one go, because at the end of the day if you're going to buy jewellery online, you need to be aware of many factors. Many eBayers won't have the information we have access to, so we're trying to simplify the buying process.

All jewellery made in Britain over a specific weight must be hallmarked. A hallmark is a stamp inside the ring that must have four symbols. Additional symbols may be used to identify the origins of the jewellery.

The four symbols that should be in every hallmark are:

1. The Sponsor's Mark - This denotes the initials of the manufacturer of the piece. It may be an individuals' initials or company initials. The Assay Office has a record of every Sponsor's Mark.

2. The Standard Mark - This is where the purity of the metal is given as a three figure number. The number is out of a thousand. 9ct gold is written as 375. This means it is 37.5% pure gold, or for every thousand parts, 375 of them are 9ct gold.  

3. The Assay Office Mark - This shows which Assay Office the piece was tested at (All jewellery is tested for purity). There are now four British Assay Offices - London, Birmingham, Sheffield and Edinburgh. London's symbol is a panther's head, Birmingham's symbol is an anchor, Sheffield's symbol is a tudor rose, and Edinburgh's symbol is a castle. Older jewellery may carry a symbol other than these, as there were more Assay Offices in days gone by. 

4. The Date Letter - Quite simply, a letter. The style of lettering shows the year the piece was hallmarked. 

Metal Purities

The metal standards of fineness (or how pure the metal is) are given below.

Silver - 925 is 92.5% pure silver. This is known as sterling silver. Another purity of silver is Britannia, which is 958.4 (written as 958 or 95.8% pure). This is not so common. Sterling silver is a popular fashionable choice of metal as it costs less than gold and is easy to work with. It's a good choice for budget buys and day to day wear. A lot of silver jewellery doesn't require a hallmark, but will usually carry a 925 stamp. Sometimes silver is rhodium plated to help prevent it from tarnishing. All untreated silver will tarnish, and it's best to clean it regularly. Most jewellers can offer a cleaning service. Other silver purities exist, although they are found mainly in foreign jewellery.

9ct gold - 375 is 37.5% pure gold. When gold is coloured (such as white gold or rose gold), it doesn't affect the minimum amount of gold, as it is other metals that produce the colour. Although a lower purity, this is a good choice for day to day wear as it is quite hardy. White gold should be rhodium plated to make it look whiter as it naturally is a 'champagne' colour.

18ct gold - 750 is 75% pure gold. This is a popular choice of metal as it is much more pure than 9ct, and is excellent for setting stones such as diamonds. Again, the white metal should be rhodium plated. This metal looks clean and bright and can be worn day to day. 

22ct gold - 916.6 is written as 916 (or 91.6% pure gold). The traditional choice of wedding bands, this is the purity of metal most commonly found in Asian jewellery. It is rather soft however, so not necessarily the best choice for day to day wear. 

Platinum - 950 or 95% pure. The best metal for high quality diamonds to be set in. This is an extremely dense metal in comparison to the other metals and requires a skilled jeweller to work it. Sometimes it is rhodium plated, but polished platinum with a bare surface looks as good without. Platinum is very expensive, but worth the investment. Some older jewellery may have a platinum setting, but the rest of it is 18ct. We would recommend having a piece of jewellery made of one or the other as they tend to last longer.

A brief note on palladium - palladium jewellery is set to come soon. We don't know what effect it will have on the marketplace, but we'll update the guide when we have more information. 

Please bear in mind that the above information is for general guidelines only. Day to day wear doesn't include the gardening! Use of common sense is important. Just because diamonds are one of the hardest substances known to man doesn't mean they won't pop out of a setting whilst you're washing up. All jewellery will become worn eventually, and day to day wear in particular puts a lot of fine scratches on the surface of a ring.

You may have bought a piece of jewellery which has a stamp in the shape of a set of scales rather than the ones given above (although it will have a number in the scales to denote the purity). Don't panic, this is a common control mark. It means that piece was made in a region that conforms to certain hallmarking guidelines. You may find that you've come across another set of numbers and don't know what they mean. Any other caratage of metal is possible up to twenty-four carat gold, but these are not as common is Britain. These are likely to have been put there by the manufacturer, and may not reflect the purity. If you wish to have a hallmark put on these items, your jeweller can advise you. There is a charge for hallmarking, usually around £20 through a jewellers, although it may vary by region and metal type.

If a piece of jewellery changes colour, it is simply corrosion. Many customers assume that a piece of jewellery does this because it is poor quality, but this is not necessarily the case. It may be that perfumes, moisturisers, and even sweat has left its residue. Any good jeweller should be able to clean or polish off a surface stain. It may sound a bit unsavoury, but a build up of dead skin and sweat can cause a surprising amount of damage. The best way of avoiding this for home cleaning is a soft toothbrush in a mild soap solution and thoroughly rinsing. This isn't applicable to all jewellery, however, so please again exercise caution. If you are unsure, please consult a jeweller. We can advise on jewellery care over the phone, so please visit our shop for contact details.

For further information on hallmarks, the Assay Offices each have their own websites. These go into a lot more detail on stamps and sell resources to help amateurs and enthusiasts.    

If you find this resource useful, please take the time to vote. If we can make consumers more aware, the marketplace becomes a better place to trade in.

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