Tarnished Silver: Why Silver Turns Black

Tarnished Silver: Why Silver turns black


Does your Sterling Silver tarnish?

Summer months can be a nightmare for lovers of Silver, when, for no obvious reason, your Silver jewellery doesn’t look as lustrous as it should. Here we explore some reasons why this happens.

First of all what causes the discolouration?

Silver turns black when kept in the air because it reacts with sulphur compounds such as hydrogen sulphide (H2S) present in air. The phenomenon is called corrosion and, for silver in particularly, is called tarnishing. The black substance formed is silver sulphide.

This is a common issue with Silver, even British hallmarked 925 solid Silver can tarnish, it’s not a fault, it’s a natural occurrence. It is common and certainly not a sign there is a quality issue with your Sterling Silver and can infact be used to provide a decorative contrast against polished Silver to highlight detail, but, how can we prevent it from happening?

Sterling Silver is an alloy and is created when copper is added to pure Silver in order to make the resulting metal more durable and less soft. Usually, Sterling Silver has a purity of 92.5%, which is what the 925 stamp indicates (925 parts per 1000) meaning that 7.5% of the alloy is made of copper and other metals (eg. zinc).

Copper oxidises when exposed to the atmosphere especially when there is high humidity moisture. The Copper metal reacts with Oxygen, resulting in the formation of an outer layer of Copper Oxide. This reaction on Silver results in tarnishing and taking on a blackened appearance.

So, what are the common causes and how to avoid tarnishing?

1. Moisture and Humidity.

Summer months usually result in an increased moisture level on our skin (dare we say, perspiring, although we all know ladies glow!). Hot nights, and long sunny days, more showering, etc all increase moisture exposure, which can lead to tarnishing.

Solution: avoid wearing jewellery while sleeping, and showering/bathing.

Remove jewellery from bathrooms especially while showering, which can create a humid atmosphere (we all know what us ladies are like for popping trinkets on the side!).

2. Cosmetics and Sunscreen

Many beauty cosmetics, especially sunscreens, contain zinc oxide and other small chemical particles, this exposure to Sterling Silver results in tarnishing.

Solution: apply sunscreen before donning jewellery making sure it is well absorbed before doing so. This can reduce, but not stop, the tarnishing process.

Apply jewellery after makeup, we’ve all heard of the saying ‘last on first off’ with regard to wearing pearls as they are so delicate, by adopting this practice with silver and wiping with a dry soft cloth after wearing, it can again reduce tarnishing.

3. Swimming baths

Chlorinated swimming pools are a huge NO NO. Chlorine reacts with the Copper within the Silver and results in tarnishing and, even worse, can cause pitting. Again we stress this is not a fault with the Sterling Silver, it is a natural reaction when the Copper within Sterling Silver meets Chlorine.

Solution: remove all jewellery prior to swimming especially in chlorinated water.

4. Perfumes and sprays

Perfumes and sprays contain chemicals, again these can react with your Sterling Silver and cause tarnishing.

Solution: spray perfume onto your skin and allow it to dry fully before wearing your jewellery.

5. Diet

Not obvious, but your diet can actually affect your silver.
A diet which contains a higher amount of sulphur rich foods, such as eggs, garlic seafood, etc. can produce sweat (or perspiration for ladies) to have a higher concentration of sulphur compounds, which will cause a reaction with the copper within Sterling Silver and accelerate tarnishing.

Solution: Avoid high sulphur foods, there are lots of low sulphur foods available.
Never keep your Sterling Silver jewellery next to a boiled egg, it will oxidise/tarnish it!!!

* Please keep your diets healthy and varied *

So you can see how hot, humid, sunny days, spent swimming, applying sunscreen, increased showering, spray deodrant and perfume, eating a diet which is Sulphur rich, and make up can all contribute to tarnished Sterling Silver.

Solution: Avoid the above where possible, although no one is expecting you to put your life on hold for the sake of keeping your jewellery tarnish free.
Wipe your jewellery after wearing it and before storing it.

A small amount of tarnish can be easily removed using a Silver polishing cloth.
Store Sterling Silver in an airtight box where possible to limit exposure to humidity.
I hope this helps and you all have an amazing summer!


Written by Toni Hardwick – Grounded Soul Jewellery

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