Why Does Brass Turn Green? Causes, Cleaning Tips, and Prevention

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Why Does Brass Turn Green? 

I bet this was the question on your mind the morning you noticed a green taint on your newly bought brass jewelry. What about your skin? Did it turn green too?

Are you one of those with skin that’s prone to reacting with jewelry? It might be difficult to understand that a piece of “white” jewelry you bought has now developed a greenish coloring.

No, you’re not turning into a green alien, the green coloration won’t gradually turn your whole body green.

First, let’s talk about brass,

What is Brass?

Brass is an alloy made from copper and zinc, generally with a 67% copper to 33% zinc ratio. This copper alloy initially has a dull, golden-yellow color, it can turn into a green tint over time when exposed to air.

We use brass to produce many things which are found in our everyday life, from doorknobs to bathroom fittings, home decorations, even on parts of some machinery.

So now let’s talk about the elephant in the room, why does brass turn green?

 The green discoloration happens due to a process known as patination. Depending on whether the brass is coated or plated, it can produce greenish corrosion on its surface over time which is called patina.

What is Patina?

The green residue you’ve noticed on your jewelry is called patina—a cute term, don’t you think?

Patina is a type of light corrosion that can develop on metals like brass, copper, silver, and bronze. It’s similar to how iron rusts and turns red when exposed to the air for too long.

Do you know how iron steels would rust and turn red when left in the open for too long? Well, that’s what the green residue on your jewelry is. 

Patina appears as a result of a chemical process between a metal, the ions in the air, and sweat from your skin. Patina is to brass, as rust is to iron, but both are types of corrosion resulting from a process called oxidation.

I won’t go into the chemical details of oxidation, but in simple terms, oxidation is when a metal reacts with molecules and ions in the air.

This reaction causes the metal to lose some of its properties, and that’s why rust, or in the case of brass, bronze, copper, and zinc; patina happens.

The presence of copper in brass alloy makes it possible for its alloys to turn green. This happens because the copper oxidizes with oxygen and other elements in the air, creating that beautiful green layer! Fortunately, this patina is fairly easy to clean off.

But, your nearly brand-new jewelry isn’t going to rust away like iron would. Instead, it will simply develop a patina layer that you can easily clean off.

The green residue you see isn’t as damaging as rust. Instead, this green layer forms a protective coating on your jewelry. Once the patina has fully developed, the process naturally stops.

When brass turns green, it’s normal. Some people may notice a green discoloration on their skin after wearing jewelry made of copper alloys, such as brass, bronze, or sterling silver, for a long period.

This green discoloration happens because copper chelates from the jewelry can transfer to your skin. It’s a normal and harmless, so there’s no need to worry.

Some people may think that this green discoloration or the green goop, is a metal allergic reaction from wearing copper alloy jewelry, which of course isn’t true.

I remember thinking that the Statue of Liberty’s always-green color was a paint job, a perfect one at that too, but the reality? In case you didn’t know, it was made from copper, hence the reason it’s green all year round!

So, having read this far, why does brass turn green?

How Do You Get Rid of Patina?

Fortunately, removing the green patina layer is straightforward. Here are some effective methods:

1. Soap and Water: If the patina layer isn’t much, simply washing the jewelry with soap and water can do the trick. You can use a soft brush to gently scrub the surface, then rinse well and dry with a soft cloth.
2. Cola Soak: For jewelry like earrings or necklaces, try using cola. Dip the jewelry into the cola and let it sit for a few hours. The patina would clear off by the time you take it out of the cola, then rinse it with water and dry.
3. Lemon and Baking Soda Paste: Mix lemon juice with baking soda to create a paste. Apply this paste to a polishing cloth, then gently rub the surface of the jewelry.

Is Brass Hypoallergenic? Is Brass Nickel-free?

Like we said earlier, brass is an alloy that contains copper and contains copper and zinc, though sometimes, it may include some percentages of other metals like lead, and nickel. 

The presence of nickel in brass is what makes it allergic to people sensitive to it. The nickel would cause an allergic reaction and would result in symptoms that may include red rashes, blistering, itchiness and some raise bumps on the area where the brass jewelry was worn.

Brass allergy is symptomatically similar to other metal allergy symptoms, this is because, for most people, brass allergy is caused by nickel sensitization (that means they are allergic to nickel).

How To Prevent A Patina From Forming?

If you want to keep your brass jewelry from developing a green patina, There are some available options to follow:

1. Use Clear Nail Polish Coating: The easiest option is by using nail polish and coating around it, or the surface that comes in contact with your sensitive skin, this will also stop green discoloration of your skin by the brass jewelry.
2. Use a Lacquer Coating: Have your jewelry coated with lacquer, this would drastically reduce, (even stop) the rate at which your brass jewelry turns green.
3. Opt for Metal Plating: Have your jewelry plated with other metals such as 14k – 18k gold and platinum, this will prevent your jewelry from corrosion and allergic reaction in case there was a percentage of nickel present in the alloy jewelry.

Interesting reads 

• Onion allergy, garlic allergy, or Intolerance? This sure helps!
• 60+ Massive List of Household Items That Contain Nickel You Didn’t Know
• 5 Best Nickel Free Cookware For Nickel Free Food

Conclusion

We hope this article has thoroughly answered your question, “Why does brass turn green?” and provided valuable insights on caring for your brass jewelry.

We’d love to hear your thoughts! Have any additional questions or tips? Share your comments with us.