Does 18k Gold Turn Green?

Gold has long been cherished for its timeless beauty and durability. However, a common concern among jewelry enthusiasts is whether 18k gold, renowned for its luxurious composition, can turn green over time.

In this guide, we delve into the factors behind green discoloration, the metals used in 18k gold alloys, and steps to prevent this phenomenon.

I. Green Discoloration:

The green tint that is sometimes created by jewelry is called verdigris. It is a type of corrosion that occurs when certain metals, such as copper, silver, and brass, react with oxygen and moisture. The green color is caused by the formation of copper acetate.

II. Understanding Gold Alloys and Discoloration:

Pure gold, characterized as 24-karat gold, is renowned for its radiant beauty but is inherently soft and malleable, rendering it less suitable for everyday jewelry due to its susceptibility to scratches, dents and warping. To bolster its resilience while maintaining its captivating allure, gold is ingeniously combined with other "lesser" metals to create alloys. These alloys not only change gold's structural integrity but also introduce color variations and attributes that cater to a diverse range of jewelry preferences.

The Intricacies of 18k Gold Alloys: Among these alloy compositions, 18-karat gold emerges as a popular choice among jewelry buyers. Comprising 75% pure gold and 25% alloyed metals, it strikes a delicate balance between durability and aesthetic appeal. The alloy metals incorporated into 18k gold can include copper, silver, zinc, and even palladium. The specific blend of these metals can significantly influence the alloy's susceptibility to discoloration, particularly the infamous green hue that concerns many jewelry enthusiasts.

III. Influence of Alloy Metals on Discoloration: 

Copper, one of the primary alloy metals found in many gold jewelry compositions, has the tendency to react with air and moisture. This interaction leads to the formation of copper oxide, which manifests as the dreaded green discoloration on the skin beneath the jewelry. While copper plays an integral role in crafting the warm and rich hues of rose gold, its potential for discoloration is an aspect that both jewelers and wearers need to consider.

The role of other alloy metals, such as silver and zinc, should also be considered. While they may not induce the same green discoloration as copper, their presence can contribute to the overall stability and durability of the alloy. Moreover, alloying metals like palladium, a member of the platinum group, can introduce hypoallergenic properties to the gold alloy, making it more suitable for individuals with sensitivities.

a. Why Gold Jewelry Turns Green:

 Discoloration in gold jewelry, commonly seen as a greenish hue on the skin, is not actually a result of the gold itself but rather the interaction between the alloy metals and the wearer's skin chemistry.

b. Copper's Role in Green Discoloration: 

Copper, an elemental metal often incorporated into gold alloys, is a key protagonist in the saga of green discoloration. Widely known for its distinct warm hues and malleable nature, copper lends its unique character to the alloy. However, it also possesses a particular penchant for reacting with air and moisture. When exposed to the humid environment and the natural moisture of the skin, copper embarks on a transformative journey.

c. The Chemistry of Transformation: 

As copper meets the trifles of air and moisture, it forms copper oxide – a compound of copper and oxygen. This compound is a vibrant green, and it's this stunning transformation that manifests as the greenish tint on the skin. But why does this reaction primarily happen on the skin? The answer lies in the delicate balance between the alloy's composition and the wearer's environment.

d. Moisture and Oxidation: 

Moisture acts as a catalyst, accelerating the process of oxidation, the chemical reaction where a substance combines with oxygen. Areas with higher humidity levels or instances of sweating amplify this reaction, expediting the formation of copper oxide. The marriage of copper, air, moisture, and skin becomes a symphony of chemistry, culminating in the manifestation of the green hue.

e. Personal Chemistry Matters: 

However, the story doesn't end with the alloy alone. Individual skin chemistry wields its influence, adding an extra layer of complexity. Our skin's pH – a measure of its acidity or alkalinity – plays a significant role. Those with more acidic skin chemistry are more likely to witness the captivating green transformation. The increased acidity speeds up the oxidation process, intensifying the interaction between copper and oxygen.

IIII. Preventing Green Discoloration: 

While green discoloration is more commonly associated with lower-karat gold and base metals, it can still occur with 18k gold under certain conditions. To prevent this phenomenon and maintain the allure of your gold jewelry, consider these strategies:

1. Opt for Nickel-Free Alloys:

Nickel, a notorious contributor to allergic reactions and discoloration, can disrupt the harmony of your gold jewelry. Choose nickel-free gold alloys when possible to minimize the risk of both skin irritation and the onset of green discoloration. This conscious selection can lay the foundation for a harmonious relationship between your skin and jewelry.

2. Regular Cleaning Ritual:

A simple yet effective countermeasure against discoloration is regular cleaning. Gently cleanse your gold jewelry using a mild soap and lukewarm water. This ritual helps banish accumulated dirt, oils, and potential irritants that might contribute to the emergence of the green hue. Through consistent care, you can thwart the subtle advances of discoloration.

3. Embrace Proper Storage Practices:

Like a haven for treasures, your jewelry storage can play a role in the battle against discoloration. Opt for a dry, cool environment that minimizes exposure to moisture and air. This calculated choice can impede the oxidation process, preventing the evolution of green tints. Avoid the lure of humid settings that might hasten the transformation.

4. Avoid Harsh Chemicals:

Avert the clutches of harsh chemicals that can act as catalysts for discoloration. Whether they lurk in cleaning products, lurk in chlorinated pool waters, or lurk within cosmetics, these substances can accelerate the oxidation of metals in your gold jewelry. Vigilance in removing your jewelry before encountering such substances is a potent preventive measure.

5. Personal Care Rituals:

In the delicate choreography of personal care, timing is everything. Apply lotions, perfumes, and cosmetics before adorning your jewelry. This sequence ensures that the metals in your jewelry avoid direct contact with substances that could provoke the insidious process of oxidation. By orchestrating these steps, you can preserve the integrity of your jewelry's appearance.

6. The Consultation of Professionals:

Should the unsettling green hue stubbornly persist despite your best efforts, the guidance of a professional jeweler can be invaluable. Their expertise can illuminate the root causes of discoloration, enabling them to recommend tailored cleaning methods or even alternative materials that minimize the risk of such an occurrence.

7. Protective Barrier: Clear Nail Polish

For a creative and budget-friendly solution, consider applying a thin layer of clear nail polish to the inner surface of your jewelry. This transparent shield acts as a barrier between your skin and the metal, reducing direct contact and the potential for oxidation. While this method may need occasional reapplication, it can be effective in curbing the appearance of green discoloration.

8. Rhodium Plating:

If your 18k gold jewelry is prone to discoloration, inquire about rhodium plating. Rhodium, a member of the platinum group metals, is highly resistant to tarnishing and corrosion. Many jewelers offer rhodium plating services, which involve applying a thin layer of rhodium over the gold. This not only enhances the jewelry's appearance but also acts as a shield against the factors that trigger discoloration.

9. Skin Barrier: Clear Jewelry Coatings

Some specialty products are designed to create a protective layer between your skin and the jewelry. These clear coatings can be applied to the jewelry's surface, forming a barrier that prevents direct contact with your skin. While this solution might require periodic reapplication, it can offer an added layer of defense against green discoloration.

10. Rotation and Rest:

Give your jewelry a breather by rotating the pieces you wear regularly. Wearing the same jewelry day in and day out can expose it to continuous moisture, oils, and environmental factors, potentially accelerating discoloration. By allowing your jewelry to rest between wearings, you give it a chance to recover from potential irritants.

11. Purchase From Trusted Sources:

When acquiring new pieces, opt for reputable jewelers and brands known for their quality and attention to detail. Established sources are more likely to use high-quality alloys and manufacturing processes that minimize the risk of discoloration. Research and reviews can guide you toward trusted sources that prioritize the longevity of your jewelry.

12. Professional Maintenance:

Periodic professional maintenance can extend the life of your jewelry and minimize discoloration risks. Jewelers can inspect your pieces, identify early signs of potential issues, and perform necessary cleaning or restoration. This proactive approach can catch minor concerns before they escalate into visible discoloration.

13. Skin Protection: Barrier Creams

Consider applying a thin layer of barrier cream to the areas of your skin that come into contact with jewelry. These creams create a protective barrier that can help prevent direct contact between your skin and the metals in the jewelry, reducing the likelihood of oxidation and discoloration.

By incorporating these additional prevention methods into your jewelry care routine, you empower yourself with a diverse array of strategies to combat green discoloration. Each method adds a layer of defense, collectively contributing to the preservation of your 18k gold jewelry's exquisite appearance. 

V.  How to Remove the Green Tint:

Here are some more details on how to perform these methods: 

a. Wash the Area with Soap and Water:

• Start by mixing a small amount of mild dish soap or hand soap with warm water in a bowl or container. Make sure the soap is gentle and doesn't contain harsh chemicals.
• Dip a soft cloth or sponge into the soapy water and gently scrub the affected area of the jewelry.
• Pay special attention to any crevices or intricate designs where dirt and grime might accumulate.
• Rinse the jewelry thoroughly under lukewarm running water to remove the soapy residue.

b. Apply a Paste of Baking Soda and Water:

• In a separate bowl, create a paste by mixing baking soda and water. Start with a small amount of baking soda and add water gradually to form a paste with a toothpaste-like consistency.
• Use a soft cloth or your fingertip to apply the baking soda paste directly onto the green-tinted areas of the jewelry.
• Let the paste sit on the jewelry for about 10 to 15 minutes. This allows the baking soda to react with and help lift the verdigris.
• Avoid letting the paste sit for too long, as prolonged exposure to baking soda might affect certain types of jewelry.
• After the allotted time, rinse the jewelry thoroughly with lukewarm water to remove the baking soda paste.

c. Soaking in Vinegar:

• Submerge the affected jewelry in a bowl of white vinegar for 30 minutes to an hour. Make sure the jewelry is fully immersed.
• After soaking, gently scrub the jewelry with a soft toothbrush to help loosen the verdigris.
• Rinse the jewelry thoroughly with water to remove any vinegar residue.
• Dry the jewelry completely before storing or wearing it.

d. Using Toothpaste:

• Apply a small amount of non-gel toothpaste (preferably mild, white toothpaste) to a soft cloth.
• Gently rub the toothpaste onto the jewelry, focusing on the areas with the green tint.
• Use a soft toothbrush to scrub the jewelry, applying light pressure to remove the verdigris.
• Rinse the jewelry with water to remove the toothpaste residue.
• Dry the jewelry thoroughly. 

e. Using Rubbing Alcohol:

• Dampen a cotton ball or soft cloth with rubbing alcohol.
• Gently rub the affected areas of the jewelry to dissolve the verdigris.
• If necessary, use a soft toothbrush to scrub more stubborn areas.
• Rinse the jewelry with water to remove any residue from the rubbing alcohol.
• Dry the jewelry completely.

f. Using a Commercial Jewelry Cleaner:

• Read and follow the instructions provided on the commercial jewelry cleaner product label carefully.
• Typically, you'll need to apply the cleaner to the jewelry, allowing it to sit for a specified amount of time.
• Gently scrub the jewelry with a soft toothbrush or cloth to help remove the verdigris.
• Rinse the jewelry thoroughly with water to remove any cleaner residue.
• Dry the jewelry completely.

RELATED Q+A:

Q: Why does the green tinge only appear in some people? 

A: The green tinge only appears in people who have acidic sweat or skin. The acids in sweat or skin react with the metal in the jewelry and cause the oxidation reaction that produces the green tinge.

Q: Can the green tinge damage my skin? 

A: No, the green tinge will not damage your skin. It is simply a cosmetic issue. However, if you have sensitive skin, you may experience some itching or irritation.

Q: Is the green tinge harmful? 

A: The green tint, known as "verdigris," is a patina that forms on metals like copper, brass, and bronze due to exposure to moisture and environmental factors. While it's not directly harmful to health, it can indicate corrosion and potential weakening of the metal over time. Verdigris can affect the aesthetics of jewelry, potentially lead to skin irritation or discoloration, and impact gemstones if present. Cleaning and preventive measures are advised to address and avoid the formation of verdigris.

Q: What if I have an allergic reaction to the jewelry? 

A: If you have an allergic reaction to the jewelry, you may experience symptoms such as itching, redness, swelling, or hives. In severe cases, an allergic reaction to jewelry can even lead to anaphylaxis. If you experience any of these symptoms, you should remove the jewelry immediately and seek medical attention.

Q: Is the green tint rust?

A: No, the green tint known as verdigris is not rust. Rust is a specific form of corrosion that occurs on iron and iron-based metals when they react with oxygen and moisture. It appears as a reddish-brown flaky substance that can cause structural damage to the metal.

Verdigris, on the other hand, is a patina that forms on copper and copper alloys like brass and bronze when they react with moisture, air, and other environmental elements. It appears as a greenish-blue or greenish-gray coating. While both rust and verdigris are forms of corrosion, they occur on different types of metals and have distinct visual characteristics.

Conclusion: 

While 18k gold is less prone to discoloration compared to lower karat gold or base metals, the potential for green discoloration still exists due to the presence of alloy metals like copper. Understanding the factors contributing to discoloration and adopting preventive measures can help you enjoy the beauty of your gold jewelry without worrying about unwanted changes in its appearance. 

By selecting high-quality alloys, practicing proper care, and being mindful of your individual skin chemistry, you can keep your 18k gold jewelry shining brightly for years to come. Thanks for reading!