Why Does Brass Turn Green - All You Need To Know!

March 2, 2020

Reading time for this article is 4 mins

why does brass turn green

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 among those with the leach-prone skin? It doesn’t make any sense that an entirely “white jewelry you bought has now magically turned into green!

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 of copper; an alloy made using copper and zinc. Brass is customarily made of copper to zinc ratio in the form of 67% and 33%, respectively. This copper alloy, though dullish yellow in color, a dullish-golden yellow, would turn green after some time, as long as it kept in the open 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?

Depending on the use or absence of coating, also known as plating, brass metals would turn green after a while.

When that happens, the brass jewelry will produce greenish corrosion on the its surface, and that green disposition is called patina.

What is Patina?

The green residue which you noticed on your jewelry is called patina, cute name, right?

Patina is a type of corrosion, albeit, light corrosion on some metals like brass, copper, silver, and bronze.

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 occurs 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 they both are a type of corrosion due to a term called oxidation.

I won’t go into the chemical definition of oxidation. However, in plain English, oxidation means the metal is reacting with the molecules and ions in the air.

This reaction makes 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 content of the metal oxidizes with the oxygen and other elements in the air, to form this beautiful green layer! (which is totally, easily washable)

But no, your almost brand-new patina-infested, (kidding,) your brand new jewelry is not going to rust away as iron would completely. It would only get covered in the patina layer until you clean it off.

The green residue isn’t as vicious as rust on metal, this green substance is using the green layer to protect your jewelry, and once it has completely covered the jewelry, then the patina process stops.

When brass turns green, you must know that it is a natural process. 

Some people do experience a green discoloration on their skin after wearing a copper alloy (brass, bronze, sterling silver jewelry) jewelry for some duration of time.

This green discoloration is as a result of copper chelates entering the skin, and it is a normal, and unharmful phenomena, and is absolutely no reason 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, haven read this far, why does brass turn green?

How Do You Get Rid of Patina?

It’s straightforward to get rid of the gree layer on copper alloy jewelry.

  1. Try soap and water, if the patina layer isn’t much.
  2. Cola fix – if it is a jewelry, like an earring, or necklace, dip the jewel into the cola, then let it sit for a few hours, the patina would clear off by the time you take it out of the cola.
  3. by using Lemon/soda combo – apply it on you polish clothe, then gently, but thoroughly wipe the surface of the jewelry, and watch as the green deposition disappears! 

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).

Interesting reads

How To Prevent A Patina From Forming?

There are some available options should you want to avoid your brass jewelry from turning green. 

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.

Have your jewelry coated with lacquer, this would drastically reduce, (even stop) the rate at which your brass jewelry turns green.

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.

Here are some stunning brass jewelry on Amazon

Conclusion

We hope you wouldn’t have to ask the question “why does brass turn green?” again. Hopefully, this article was able to answer your question and more.

What are your thoughts on “why does brass turn green”?

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Welcome to Too Allergic. I’m Agnes, I’m not an allergy specialist nor a medical professional, and I’m not posing as such. However, I do enjoy researching and collecting data about things that matter to me, which is about my mom and my son’s allergic condition. Please, do not substitute any information on tooallergic.com for professional advice from a licensed medical practitioner, always confirm with your doctor first.