Why Does Gold Turn Black?

Gold, prized for its beauty and durability, can sometimes lose its shine and turn black, leaving many owners curious about the reasons behind this phenomenon. In this article, we'll explore the factors, including skin chemistry and external elements, that can cause gold to tarnish. 

We'll also provide easy cleaning methods to restore your gold's luster and help you enjoy its elegance for years. Let's uncover the secrets behind gold's transformation!

Oxidation and Tarnish

One of the main reasons why gold can turn black is oxidation and tarnish. Oxidation is a chemical reaction that occurs when a substance loses electrons and combines with oxygen. Tarnish is a thin layer of corrosion that forms on the surface of a metal as a result of oxidation.

You may be wondering how gold, which is considered a noble metal, can undergo oxidation and tarnish. After all, gold is known for its stability and resistance to corrosion. The answer lies in the fact that most gold jewelry is not made of pure gold, but of gold alloys.

Gold alloys are mixtures of gold and other metals, such as copper, silver, or nickel. These metals are added to gold to make it more durable and suitable for use in jewelry, as pure gold is relatively soft and malleable. However, the presence of these additional metals in the alloy can make gold more susceptible to discoloration when exposed to oxygen.

The impact of oxygen on gold depends on the type and amount of metals that are mixed with gold, as well as the environmental factors that affect the oxidation process. Some of these factors include air, humidity, and pollutants.

Air contains oxygen, which can react with the metals in the gold alloy and form oxides. Humidity can accelerate the oxidation process by providing moisture and electrolytes. Pollutants, such as sulfur dioxide or carbon monoxide, can also interact with the metals in the gold alloy and cause discoloration.

When these oxides form on the surface of your gold jewelry, they can give it a black or tarnished appearance. The most common oxides that cause gold to turn black are copper oxide and silver oxide, which are formed by the reaction of copper and silver, respectively, with oxygen. Copper and silver are often used as alloying metals in gold jewelry, especially in lower-karat gold (e.g., 14 or 18 karats), which contains a higher percentage of these metals than higher-karat gold (e.g., 22 or 24 karats).

To avoid oxidation and tarnish, it is best to keep your gold jewelry away from sources of oxygen, moisture, and pollutants. You can also protect your gold jewelry by applying a thin layer of clear nail polish or lacquer, which can act as a barrier against oxidation.

Chemical Reactions with Skin and Cosmetics

Another reason why gold can turn black is chemical reactions with substances on your skin or in the environment. These substances can include perfumes, lotions, cosmetics, and even your own sweat. These substances can contain acids and other chemicals that can react with the metals in the gold alloy and cause discoloration.

One of the most common chemicals that can cause gold to turn black is chlorine, which is found in many household products, such as bleach, disinfectants, and swimming pool water. Chlorine can react with the metals in the gold alloy and form chlorides, which can have a dark or black appearance. Chlorine can also damage the structure of the gold alloy and make it more brittle and prone to cracking.

Another common chemical that can cause gold to turn black is sulfur, which is found in many natural and synthetic substances, such as eggs, garlic, onions, rubber, wool, and leather. Sulfur can react with the metals in the gold alloy and form sulfides, which can also have a dark or black appearance. Sulfur can also cause the gold alloy to become dull and lose its shine.

Other chemicals that can cause gold to turn black include acids, such as citric acid, acetic acid, and lactic acid, which are found in many fruits, vinegar, and dairy products. These acids can corrode the metals in the gold alloy and form salts, which can have a dark or black appearance. Acids can also etch the surface of the gold alloy and make it more rough and uneven.

To prevent chemical reactions with your gold jewelry, it is advisable to minimize exposure to substances that contain chlorine, sulfur, or acids. You can do this by removing your gold jewelry before engaging in activities that involve these substances, such as swimming, cleaning, or using skincare products. You can also clean your gold jewelry regularly to remove any residues or traces of these substances.

Sulfur and Atmospheric Conditions

A third reason why gold can turn black is the reaction between gold and sulfur compounds present in the atmosphere. These sulfur compounds can include hydrogen sulfide, sulfur dioxide, and sulfur trioxide, which are produced by natural and human activities, such as volcanic eruptions, fossil fuel combustion, and industrial processes.

These sulfur compounds can react with the metals in the gold alloy and form sulfides, which can have a dark or black appearance. This reaction can be influenced by the atmospheric conditions, such as temperature, humidity, and pressure. For example, higher temperatures can increase the rate of the reaction, while higher humidity can provide moisture and electrolytes that can facilitate the reaction.

The exposure to sulfurous gases can contribute to the blackening of gold, especially in areas with high levels of air pollution or volcanic activity. This can affect not only gold jewelry, but also gold coins, bars, and statues. For instance, the Statue of Liberty, which is made of copper, has turned green over time due to the reaction of copper with sulfur dioxide and other pollutants in the air.

To protect your gold from sulfur and atmospheric conditions, it is recommended to store your gold jewelry in a dry and airtight environment, such as a jewelry box or a ziplock bag. You can also use anti-tarnish strips or silica gel packets, which can absorb moisture and sulfur from the air and prevent oxidation and tarnish.

Impurities in Gold Alloys

A fourth reason why gold can turn black is the presence of impurities in gold alloys. Impurities are substances that are unintentionally or intentionally added to gold during the refining or alloying process. These impurities can include metals, such as iron, zinc, or lead, or non-metals, such as carbon, oxygen, or nitrogen.

Impurities can affect the color, hardness, and durability of gold alloys. They can also affect the chemical reactivity of gold alloys, making them more prone to discoloration when exposed to oxygen, moisture, or other substances. Impurities can also cause defects or irregularities in the structure of gold alloys, which can make them more susceptible to corrosion and wear.

One of the most common impurities that can cause gold to turn black is iron, which is often used as a cheap filler metal in gold alloys. Iron can react with oxygen and form iron oxide, which has a dark or black appearance. Iron can also react with sulfur and form iron sulfide, which can also have a dark or black appearance. Iron can also make gold alloys more brittle and hard, which can affect their quality and performance.

Another common impurity that can cause gold to turn black is copper, which is often used as a base metal in gold alloys. Copper can react with oxygen and form copper oxide, which has a dark or black appearance. Copper can also react with sulfur and form copper sulfide, which can also have a dark or black appearance. Copper can also make gold alloys more malleable and ductile, which can affect their shape and size.

To avoid impurities in gold alloys, it is important to buy gold from reputable and certified sources, such as jewelers, dealers, or mints. You can also check the purity and quality of gold by looking at the hallmark, which is a stamp or mark that indicates the karat, maker, and origin of the gold. You can also use a magnet, which can attract iron but not gold, to test the presence of iron in gold alloys.

Preventive Measures for Maintaining Gold’s Luster

As you can see, there are many factors that can cause gold to turn black, but there are also many ways to prevent and fix this problem. Here are some preventive measures that you can take to maintain the luster and beauty of your gold jewelry:

Regular Cleaning

One of the simplest and most effective ways to prevent gold from turning black is to clean it regularly using mild soapy water and a soft cloth. This can remove any dirt, dust, or residues that can cause oxidation and tarnish. 

You can also use a soft-bristled toothbrush to gently scrub any hard-to-reach areas or crevices. After cleaning, rinse your gold jewelry with clean water and dry it thoroughly with a soft towel or a hairdryer.

Proper Storage

Another way to prevent gold from turning black is to store it properly in a dry and airtight environment, such as a jewelry box or a ziplock bag. 

You can also use anti-tarnish strips or silica gel packets, which can absorb moisture and sulfur from the air and prevent oxidation and tarnish. You should also avoid storing your gold jewelry with other metals, such as silver or copper, which can cause cross-contamination and discoloration.

Avoiding Chemical Exposure

Another way to prevent gold from turning black is to avoid exposing it to chemicals that can cause oxidation and tarnish. You can do this by removing your gold jewelry before engaging in activities that involve these chemicals, such as swimming, cleaning, or using skincare products. 

You can also avoid wearing your gold jewelry in places that have high levels of air pollution or volcanic activity, which can contain sulfurous gases that can react with gold.

Professional Cleaning

Another way to prevent gold from turning black is to seek professional cleaning services for your gold jewelry, especially if it is intricate or heavily tarnished. Professional jewelers can use specialized tools and techniques, such as ultrasonic cleaning, steam cleaning, or polishing, to remove oxidation and tarnish from your gold jewelry. They can also inspect your gold jewelry for any damage or defects and repair them if needed.

Myth Busting: Gold Purity and Discoloration

One of the most common myths about gold turning black is that it is related to the purity of the gold. Many people believe that pure gold does not tarnish and that only lower-karat gold can turn black. However, this is not entirely true.

As we have seen, gold can turn black due to various factors, such as oxidation, chemical reactions, sulfur exposure, and impurities. These factors can affect not only lower-karat gold, but also higher-karat gold, under certain conditions. 

For example, even 24-karat gold, which is considered pure gold, can tarnish if it contains traces of impurities, such as iron or copper, or if it is exposed to extreme heat or humidity.

Therefore, the purity of gold is not the only factor that determines its susceptibility to discoloration. The composition, quality, and care of gold are equally important factors that influence its appearance and durability.

Discover Quality Gold Accessories at IceCartel

Now that you know why gold can turn black and how to prevent and fix it, you may be wondering where to find quality gold accessories that can last a lifetime. Look no further than Icecartel, your online destination for high-quality gold accessories.

At Icecartel, we are committed to providing you with genuine and top-notch gold products that can suit your style and budget. Whether you are looking for gold chains, bracelets, rings, earrings, or pendants, we have it all. We offer a wide range of gold accessories in various designs, sizes, and karats, from 10 to 24 karats. We also offer free shipping, easy returns, and lifetime warranty on all our products.

Icecartel is more than just an online store. We are a community of gold lovers who share a passion for excellence and elegance. We are here to help you find the perfect gold accessory for yourself or your loved ones, and to provide you with tips and tricks on how to care for your gold jewelry. We also love to hear from you, so feel free to contact us anytime with your questions, feedback, or suggestions.

Don’t wait any longer. Visit Icecartel today and discover the beauty and brilliance of gold!

Conclusion

Gold is a valuable and attractive metal that can express your style and personality. However, gold can also turn black because of oxidation, chemical reactions, sulfur exposure, and impurities. These factors can affect how your gold jewelry looks and lasts. You can prevent and fix this problem by cleaning, storing, and protecting your gold jewelry properly. 

You can also keep your gold jewelry shiny and beautiful with IceCartel, your online source for high-quality gold accessories. IceCartel offers a variety of gold accessories in different designs, sizes, and karats, with free shipping, easy returns, and lifetime warranty. Gold is a timeless and elegant metal that can make you shine. Don’t let it turn black and dull. Keep it bright and beautiful with IceCartel!