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How to know the value of gold jewellery

Wednesday, October 6, 2010

Just because it glitters doesn't mean it is gold!  A little knowledge about hallmarks and the process for testing gold will help you to get the best deal if you sell your gold.

The recent rise in gold prices has meant a renewed interest in the value of our unwanted jewellery. Knowing about hallmarking and some of the most common tests that are used will ensure that when you do come to sell, you are more likely to get a good deal.

Only items that have an official gold hallmark can actually be described by a jeweller as gold in the UK and you can get more information on all the hallmarks at the British Hallmarking Council website. UK hallmarks are 375, 585, 750, 916, and 999 but as the UK is a signatory to the international convention on hallmarks, these international hallmarks are recognised in the UK as well. You should look to see if your jewellery is stamped with one of these hallmarks. It is a good idea to use a magnifying glass to see if the hallmark is one of the UK Hallmarks or one recognised under the convection. 750 indicates the jewellery is 75% pure and therefore 18k gold, 375 means 375 parts per 100 or 37.5% pure which is categorised as 9k gold. Some people think that colour is an indication of quality but the colour is a result of mixing of the gold with other metals such as copper, for example, gives a rose colour or Rhodium which gives the white gold colour.

If the jewellery does not contain a hallmark, then a simple test is to use a magnet on the jewellery as precious metals are not magnetic. However, you may get an attraction against other items in the jewellery which won't be gold, like the clasps or supports. You should therefore take care when you are using this approach.

A jeweller examining your jewellery will first look for an official hallmark but if this does not clearly identify the value of the gold, then they will test the gold. A small area of the jewellery, in a non visible spot, will be filed and acid applied to the filing (the filing is required to make sure that the test in not just being performed on the surface of the item). The jeweller is looking for a change in colour which will signify the karat of the gold.

It is also possible to buy a gold testing kit which involves you scratching the gold on a stone supplied in the kit and then testing the residue on the stone with acid. It is the process that gave rise to the expression ‘the acid test'. It is the time interval that the gold residue remains on the stone which determines the quality of the gold - 18k gold will last longer than 30 seconds. Testing higher quality gold items requires comparison of dissolve times against standard sample results.

Having some knowledge of the process means you are better equipped to get the best deal when you come to sell your gold. However, it is always recommended that you find a reputable jeweller who can make a professional assessment of the quality and value of the gold.


Author: Tony Birdsall - Antony James Jewellers, Kingston-upon-Thames, Surrey


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