WHY DOES SILVER JEWELLERY TURN BLACK?

WHY DOES SILVER JEWELLERY TURN BLACK?

This blog will help you understand the simple science behind why silver jewellery and articles tarnish over time, can this phenomenon be avoided? Can it be reversed? This blog will help you in understanding everything.   

When we open our jewellery box to wear the silver jewellery we had kept away for a few months and the products would have turned black or would have got tarnished. What comes to our mind at this point of time is, “is my silver jewellery fake?” ,“Is my jewellery made of low-quality silver?” etc

 Most of the time, what you would be seeing is called as tarnishing. The process of silver’s surface getting tarnished is called as oxidation. Let’s understand how this happens.

Silver doesn't really "turn black"

The whole product does not turn black, it’s just a thin outer layer of the product that tarnishes, underneath it is still shiny silver.

That thin dark layer is a compound called silver sulphide (Ag₂S). It forms when silver meets tiny amounts of sulphur-containing substances around us.

 

But isn't silver a very "unreactive" metal?

Yes, Silver is one of the least reactive metals, ranking among the three least reactive metals in the commonly used reactivity series. This makes it more interesting. For example, iron reacts with oxygen and hence gets rusted, but silver does not react the way iron does. But hard to react does not mean “never reacts”.

Silver reacts to sulphur in the air. Oxygen barely bothers silver, but even a small amount of sulphur can start a reaction on its surface.

 

Where does the sulphur come from?

There are no clouds of sulphur floating around. The amount is very less. But they are enough. Here are some common sources are:

• Air pollution. Gases such as hydrogen sulphide (the "rotten egg" smell, found near drains and sewers) and sulphur dioxide (from burning some fuels and from industry).
• Cosmetics and household products. Some perfumes, creams and cleaners can affect silver.

A more accurate way to say it that small amounts of sulphur-containing compounds in our surroundings react with silver.

Here is a common example of the reaction:

2Ag + H₂S → Ag₂S + H₂

Silver (Ag) reacts with hydrogen sulphide (H₂S) and becomes silver sulphide (Ag₂S). Silver sulphide is dark, so the jewellery looks tarnished/oxidised. In real life, oxygen and moisture often take part too, so the exact chemistry can be a little more complex. The main idea stays the same, the surface of the silver changes into silver sulphide.

Why does the colour change slowly?

Tarnish rarely appears black overnight. As the layer grows thicker, the look changes:

bright silver → slightly yellow → brown → grey → dark grey or black

So, a yellowish tint is just an early stage of tarnish. It is a signal to give your jewellery a gentle clean.

 Why does humidity and sweat make it faster?

Moisture forms a very thin film on the metal. This helps dissolved substances move around and react more easily. Sweat, skin oils, cosmetics and humid air all add to this. That is why a ring worn daily tarnishes faster than one kept dry in a box.

It also explains why two people can wear the same chain, and one sees tarnish in weeks while the other barely notices any. Skin, climate and habits are different for everyone.

Does black silver mean it's fake?

No, real silver tarnishes due to oxidation. If you want to check authenticity, look for a purity mark such as 925 and buy from a jeweller you trust.

How to make tarnished silver shine again ?

Because tarnish is only a surface layer, it can usually be cleaned.

1. Silver polishing cloth

Best for light tarnish. Rub gently. Using a polishing cloth will help the silver get a decent shine.

2. Mild soap and lukewarm water

Washing your jewellery can help you in removing the dirt and oils from your jewellery. Store after washing with a soft cloth, rinse thoroughly and dry properly.

3. Use Colgate tooth powder

Another simple home remedy is to place a little Colgate tooth powder on the surface of the tarnished silver, add a few drops of water and brush the surface with a soft toothbrush. Do not rub the surface too hard as it may scratch the surface of the jewellery. The mild action of the Colgate tooth powder helps remove the dark tarnish layer and can restore much of the silver’s original shine.

3. Get your silver jewellery polished from your trusted jeweller

 

How to slow down tarnishing

• Wipe after wearing. A soft cloth removes sweat and oils in seconds.
• Store separately. Keep pieces in individual pouches so they don't rub together.
• Keep it dry. Humidity speeds up tarnish. Anti-tarnish bags or cloths help.
• Wear it. Regular wear and wiping often keep silver brighter than leaving it locked away.

The one-minute summary

Silver is not a highly reactive metal, so it doesn't rust like iron. But it is sensitive to sulphur. Tiny amounts of sulphur compounds in our surroundings react with the silver surface and form dark silver sulphide. That thin layer is tarnish. It does not mean your silver is fake or ruined, and it can usually be cleaned.

It's chemistry, not damage.

 

Explore everyday silver jewellery from Sharada Silver made to be styled, worn and loved.