How to prevent silver tarnishing
Wednesday, 21 April 2021 | Victoria
Why does silver tarnish?
Sterling silver is an alloy and not pure silver (‘alloy’ means a mixture of two or more elements where at least one element is a metal). You will see sterling silver commonly marked with '925', this is because it contains 92.5% pure silver and 7.5% other base metals, usually copper. It is alloyed to make it more durable and less soft because pure silver is extremely malleable.
When the copper in sterling silver reacts with sulphur-containing gases in the air it forms a layer of copper sulphide and this is what we call tarnish. As tarnishing continues the layer of tarnish on the silver will change in colour from misty grey, to yellow, to red-brown, to blue to black.
The rate that silver tarnishes depends on the concentration of sulphur gases in the air. Going to a hot spring wearing your silver jewellery is not a good idea, nor is dipping your silver jewellery in the yolk of an egg (and also slightly odd behaviour). If relative humidity levels are high then this will also increase the rate of tarnishing as moisture quickens the rate of tarnishing.
Some packaging can also promote tarnishing due to high sulphur levels released from some paper, cardboard, foams and adhesives (never store silver in newspaper).
In addition to sulphur gases, perspiration and fingerprints can also cause tarnishing. The salt (sodium chloride) reacts with the silver to form silver chloride which can darken over time.
How to prevent tarnishing
STORE IT CORRECTLY. This is the best advice I can give to anyone wanting to slow down the tarnishing process (you cannot prevent tarnishing altogether). You need to store your items in an airtight bag thereby eliminating exposure to moisture and sulphur gases. Make sure your items are completely dry before putting them in a sealed bag. The silica gel bags you find everywhere can be reused to absorb moisture, or use anti tarnish strips. I personally store each item of my (completely dry) jewellery in a small grip seal bag and include an anti tarnish strip in each bag.
Remove your jewellery before swimming and bathing and always put on your jewellery after applying body lotion, perfume, hairspray etc. Avoid wearing jewellery whilst using cleaning products, such as bleach.
For larger silver pieces you may want to apply a wax coating to protect your silver. Renaissance Wax is widely used to preserve precious metals from tarnishing by producing a barrier that excludes moisture and oxygen from the metal surface. It was developed in the British Museum Research Laboratory in the 1950s and is widely used for conservation work.
How to remove tarnish
Even if you have followed all the advice in this article the unfortunate truth is that if you wear your silver jewellery it will gradually tarnish over time.
Follow these steps to remove tarnish:
Now I’m going to say something very controversial! Many jewellers will tell you not to use a silver dip as they contain too many harsh chemicals and will damage your jewellery. I once put a silver pendant in a dip and instead of coming out all shiny I was left with a dull, matt, whitish piece of metal. HOWEVER, there is one item of jewellery that I would put in a silver dip and that is a chain necklace. They are very hard to clean with a polishing cloth and/or soapy water and the chains I have cleaned with dip have been successful. That being said, please use dip with care and be prepared for things to go wrong!