Reasons for the darkening of yellow gold:
The reasons for gold tarnishing: There are many factors that affect the tarnishing of yellow gold, and we will review each of them below.
1. Gold purity:
- The most important factor in the tarnishing of yellow gold is its low purity. Pure 24-karat gold cannot be used to make jewelry and gold items because it is too soft. By combining it with other metals like copper and silver, various gold accessories are created.
The presence of copper in gold alloys helps increase its strength, but it is important that copper is used in the right quality and quantity.
If metals like copper and silver are not used in standard amounts in gold alloys, the tarnishing of yellow gold becomes a natural occurrence.
When buying gold, pay attention to its purity. Jewelry with an 18-karat purity, which is the most common gold purity in Iran, tends to be of good quality and has a very low risk of tarnishing or changing color compared to gold jewelry with lower purity.
2. Tarnishing due to heat:
Constant and prolonged exposure to high heat is another reason for yellow gold tarnishing. Heat causes reactions between the impurities in gold. This happens more in lower-karat gold than in 18-karat and higher gold.
3.Copper compounds:
- To increase the strength and shape of gold jewelry, jewelers use metals like copper and silver to alloy with pure gold. If the amount of copper or silver used in these alloys is not correct or precise, color changes in the gold are inevitable.
For example, if copper is used more than silver in gold alloys, tarnishing will occur. Therefore, using the correct standard proportions of each metal in gold alloys is essential.
4.Gold plating:
- Gold plating is usually done to enhance the shine, brightness, and to prevent corrosion and rusting of the base metals in gold alloys.
If the plating process is not done correctly or with the appropriate quality, gold will undergo uneven oxidation over time, creating black layers on the surface of the jewelry, losing its beauty, and requiring re-plating.
5.Chemicals:
Exposure to various chemicals such as detergents, perfumes, cosmetics, hair dye, etc., can cause gold to change color and tarnish.
Cause of Gold Discoloration
Does Pure Gold Tarnish?
Pure gold, also known as 24-karat gold, cannot be used to create jewelry on its own because it is too soft. Therefore, jewelers mix other metals such as copper, nickel, and silver into the gold to make durable and beautiful gold accessories. However, the reason jewelry tarnishes is due to these alloys.
These metals react with moisture and oxygen in the air, causing the gold to darken and lose its shine. The type of alloy used and the karat or purity of the gold play a significant role here. The higher the karat of the gold and the less copper, nickel, and other metals are used, the less likely the gold is to tarnish. Gold with a karat of 10 usually contains nickel, which not only causes allergic reactions in some people but is also a reason for the discoloration of gold jewelry.
Reasons for Skin Tarnishing with Gold
As mentioned, many factors can contribute to skin discoloration with gold. Below are some of these factors:
Use of Copper in Gold Alloy
One of the metals commonly used in gold alloys is copper. Some goldsmiths, aiming for higher profit, use low-quality copper when mixing pure gold with copper. This can cause a greenish residue on your skin when the gold is exposed to even the slightest moisture.
This phenomenon is more likely to occur in hot and humid weather. When your skin sweats, the acids present on the skin mix with the copper in the gold jewelry, leading to the formation of copper salts or oxidation of copper. These copper salts are usually green or blue in color, and they appear on the gold or jewelry and transfer to your skin, leaving a greenish stain.
Some people may mistakenly believe they are allergic to gold when seeing this, but this is not the case. In the case of an actual allergy, red pimples with itching would appear on the skin, and in that case, a doctor should be consulted.
Cause of Yellow Gold Tarnishing:
Sweating:
Sweat from some people, due to body condition, diet, and daily activities, can be very acidic. When sweating, fatty acids are released from the body, which react with the alloys in the jewelry, causing the gold and skin to tarnish.
Gold itself does not corrode, but alloys combined with it, such as silver or copper, can undergo reactions and form dark chemical compounds in humid conditions. Additionally, the sulfur present in sweat can cause green stains on the skin.
Effect of Salt and Chlorine in Pool Water:
Cause of Gold Tarnishing:
Gold containing silver and copper can tarnish when exposed to salty environments, causing black spots on the skin. For example, if salt from foods like nuts or popcorn accidentally gets under your gold ring, it can cause corrosion and change the skin’s color.
That’s why it’s important to wash your hands thoroughly as soon as they come into contact with salt. Additionally, chlorine in pool water can destroy the gold’s coating, exposing your skin directly to the alloys of silver, nickel, and copper present in the gold.
Cosmetics The Everlasting Enemy:
When cosmetic products containing harder chemicals than the metals in your jewelry come into contact with them, a phenomenon called “black dermographism” occurs, which means “black marks on the skin.” This is one of the most common causes of black spots on the skin.
The most common compounds found in cosmetics that cause this effect include zinc oxide, titanium dioxide, ferric oxide, and calamine. Zinc oxide is a main white pigment used in face powders, creams, and lipsticks. Recently, titanium dioxide has replaced it, and it can have the same impact on jewelry.
These cosmetic particles, when left on the skin, act like sandpaper. They cause abrasion to your beautiful jewelry. These compounds essentially rub against soft metals in your jewelry, including gold, silver, platinum, and nickel, leaving black residue on your skin, which can easily be washed off with soap and water.
Anemia and Certain Medications:
In the past, when the scientific reasons behind certain phenomena were not well understood, there was a belief that if black spots appeared on the body after wearing gold, it was a sign of iron deficiency. Today, thanks to scientific research, we know that anemia, iron deficiency, and certain medications cause the blood to become more acidic.
Why Does Gold Tarnish?
Simple methods to prevent gold and skin from turning black:
Now that you are familiar with the factors that cause gold to darken and ultimately affect your skin, here are a few tips to prevent or delay this from happening.
- When not using your gold jewelry, store it in a soft lint-free cloth or a special box with satin lining.
- Avoid wearing jewelry while swimming in pools or the sea due to the salt and chlorine in the water.
- Avoid exposing gold to chemicals like soap, shampoo, and dishwashing liquid.
- Be cautious not to spray perfume or cologne directly on gold jewelry.
- Before engaging in physical activities like running or exercising that cause skin sweating, it’s better not to wear jewelry.
- Remove your jewelry before doing tasks like cleaning that may cause damage or scratches to your jewelry.
- Clean your gold jewelry using appropriate cleaning solutions at the right time to remove sweat and chemical residues, preventing corrosion of the gold’s surface and reaction with your skin.
- Preferably avoid wearing jewelry while using cosmetics. If certain products cause blackening of your skin, switch to other cosmetics. However, always clean your skin after using cosmetics and before wearing gold, or clean your jewelry with suitable solutions after applying makeup.
- When going out, try to wear jewelry last, so it has minimal contact with creams, perfumes, and colognes. After returning home, remove your jewelry first, clean it if necessary, and store it properly.
- A home remedy to prevent surface corrosion of gold jewelry is to apply a layer of nail polish. This can help prevent reactions between gold and body moisture or sweat. However, after a while, the nail polish layer may wear off, so it can be reapplied as needed.
- Finally, the best method to effectively prevent darkening is re-plating your gold jewelry. Re-plating helps maintain the shine of your jewelry and prevents both gold and skin from darkening. If the gold you recently purchased caused your skin to darken, visit a jewelry store and request a free re-plating. If the store is reputable, they should offer this service at no extra charge.
Disadvantages of yellow gold color change:
Yellow gold is one of the most popular and important pieces of jewelry for women, known for its beauty and brilliance. However, when yellow gold experiences a color change or tarnishing, it can reduce its beauty and shine, causing your gold to lose its appeal.
Gold that has changed color may resemble imitation jewelry, leading some to think you are wearing fake pieces instead of real gold. Furthermore, the color change in yellow gold could be due to the poor quality of the gold and an increase in impurities, which can cause allergic reactions and skin sensitivities. Therefore, it is better to find the cause of the color change as soon as possible and address it.
Removing blackness from gold:
How to clean and shine gold?
Gold is one of the most beautiful and precious types of jewelry, and one of the reasons for its popularity is its shine and luster. Over time, gold gradually becomes dull and develops spots on its surface. If you don’t take care of your gold jewelry, it will quickly lose its appeal. Therefore, it’s important to clean them every once in a while to restore their shine. There are several methods to clean and shine gold and jewelry, and in this article, we will discuss these methods.
Cleaning gold with salt water:
The simplest method to remove the blackness from gold is using saltwater. Add 3 tablespoons of salt to half a glass of hot water. Soak your gold jewelry in this solution overnight. The next morning, rinse them with water and dry them with a soft cloth.
Cleaning gold with dishwashing liquid:
This method is one of the easiest home remedies for cleaning gold. Add a few drops of mild, phosphate-free dishwashing liquid into warm water and stir. Fill a small bowl with 1 to 2 cups of warm water, add a few drops of dishwashing liquid, and stir for about 10 to 15 seconds until fully combined. Use a very soft toothbrush to gently brush your gold jewelry. After brushing, rinse the gold with hot water and dry it. Then, polish it completely with a chamois cloth. After washing the gold, dry it with a soft, lint-free cloth. Then, leave it in the air overnight until it is completely dry.
Cause of gold turning black on the skin:
Cleaning gold with vinegar:
Another home remedy for cleaning gold is vinegar. However, continuous and frequent use of vinegar to clean gold is not highly recommended because vinegar is acidic and can cause corrosion. Add two teaspoons of salt to half a cup of white vinegar and stir. Place the gold in this solution and let it sit for a few minutes. Once the blackness on the gold is gone, remove it from the solution, rinse it with warm water, and dry it completely with a soft cloth.
Cleaning gold with toothpaste and a toothbrush:
The reason for gold turning black and how to remove it is by using toothpaste. Apply some gel toothpaste onto a cloth or toothbrush. Carefully polish your gold with the toothpaste. Finally, rinse it with water and dry it.
Polishing Gold with Lemon Juice:
One way to clean gold is by using lemon juice. In this method, you need to prepare a solution of lemon juice, some water, and a little dishwashing liquid. Place the gold piece in this solution and let it soak for a few minutes. After the gold regains its shine, rinse it and dry it with a soft cloth.
Gold turning black due to heat:
Reasons for gold turning black on the skin – Removing blackness from gold – Why does gold turn black – What is black gold – Does gold turn black – Gold turning black due to heat – Reasons for yellow gold turning black – Blackening of white gold – What causes gold to change color?
Summary:
In this article from Zarin Jewelry website (www.zarinjewel.com), we have tried to provide you with accurate and effective methods for cleaning and polishing gold. Sometimes, you may mistakenly think your gold has turned dark or black, but in reality, your gold might not be genuine. To correctly identify fake gold from real gold, read the article on how to distinguish real gold from fake.
