Why Does Silver Jewelry Darken? Unveiling the Science and Care Suggestions

Do you own silver jewelry? Have you ever taken out a piece you haven't worn for a while, only to find it's turned black or has green marks? Or maybe you've noticed that a piece you've been wearing has turned your skin green? This article will answer all your questions about silver jewelry, whether you're familiar with the topic or not. Jewelry has become an important accessory, offering various choices like gemstones, rings, pure gold, pure silver, and crystal ornaments. Gold and silver are commonly used materials, while others like stainless steel, aluminum alloy, and brass are also used. Therefore, understanding jewelry basics before making a choice is essential.

The Science Behind Silver Jewelry Turning Black

1. The blackening of silver jewelry happens due to its reaction with different substances in the air, such as oxygen, moisture, and sulfides. This process, called "rusting," creates silver oxide, which appears black and is called tarnish.

2. When silver jewelry contacts sweat, the salts and acids in sweat speed up its oxidation. People have different sweat compositions due to various factors, like hormones and physiology. Some have more acidic sweat, others less; some have higher sulfur content. These variations cause different levels of blackening, making each person's experience unique. Some can wear silver jewelry for months without losing its shine.

3. Sulfides in the air, like hydrogen sulfide, react with silver, forming dark silver sulfide. This creates black-brown spots on jewelry, affecting its appearance. Sulfur, nitrates, and oxides in the air, as well as substances like eggs and cosmetics, can corrode silver. Over time, this mix results in a layer of black silver sulfide film, starting as small spots that gradually spread, known as "tarnish."

4. Ultraviolet rays, especially sunlight, can speed up the oxidation of silver jewelry. Prolonged exposure to UV rays accelerates this process.

5. Chemicals like cleaning agents, perfumes, and cosmetics can also accelerate silver oxidation.

6. Silver's purity affects oxidation. Higher purity silver oxidizes less easily, a quality indicator for silver jewelry.

Oxidation Levels Based on Silver Content

The purity of silver jewelry affects its oxidation rate.

Pure Silver (999 purity)

Pure silver jewelry contains 99.9% silver and minimal other alloy materials. Due to its lack of impurities, pure silver jewelry is less prone to oxidation. However, even pure silver jewelry can gradually form an oxidation layer when exposed to air and other oxidizing factors, though the process is slower, and the extent of oxidation is lighter.

925 Silver (Sterling Silver)

Sterling silver jewelry, containing 92.5% silver and 7.5% other alloy materials, often copper, is the most common type. The presence of alloys makes 925 silver jewelry more susceptible to oxidation. Other metals in the alloy can trigger faster oxidation, causing the jewelry to darken over time.

800 Silver

800 silver jewelry contains 80% silver and 20% other alloy materials. This type of silver jewelry might be more common in certain regions but less prevalent on the international market. Due to its higher alloy content, 800 silver jewelry is relatively more prone to oxidation.

Other Alloy Silvers

Apart from the mentioned purities, there are other alloy proportions in silver jewelry, such as 750 silver (75% silver), and so on. These pieces tend to oxidize more readily due to their lower silver content and higher alloy composition, potentially leading to a faster oxidation process.

Selecting Silver Jewelry Resistant to Oxidation

1. Electroplating : Electroplating involves depositing a layer of metal, like platinum, gold, nickel, on the surface of silver jewelry using electrochemical deposition techniques. Opt for silver jewelry that has undergone electroplating, such as gold-plated or platinum-plated pieces. These layers provide extra protection and slow down oxidation. The quality of plating and the choice of metals significantly impact the oxidation level. Poor plating might only have a single layer, making the jewelry highly prone to oxidation, lasting only a few months, or even less for those with low silver content. Superior plating techniques can considerably delay oxidation, extending the shine for up to two to three years. For instance, Jewel Bushra uses the highest-grade eight-layer vacuum plating with a gold plating thickness of 5/1000 (0.05μm), surpassing 80% of the jewelry in the market.

2. Purity : Choose silver jewelry with higher purity, such as 925 silver (Sterling silver) or higher. Higher purity silver tends to resist oxidation.

3. Polishing : Examine the surface of the silver jewelry for smoothness, scratches, or flaws. A smooth surface can reduce the formation of oxidation spots.

Maximizing Oxidation Delay (Maintenance Tips)

1. Regular Wear : The best way to maintain silver jewelry is to wear it every day, as the natural oils from your body lend it a warm and natural shine (though some individuals might have an exception, with sweat components that blacken silver). Avoid prolonged exposure to moist environments. When not wearing it, store it properly, preferably in a sealed bag to prevent oxidation through contact with air.

2. Periodic Cleaning : Use mild soapy water or specialized silver jewelry cleaning solutions to gently wipe the jewelry with a soft cloth, removing dirt and sweat stains. Alternatively, apply a small amount of toothpaste to the silver, add water, rub gently to create small bubbles, and rinse with water to restore the shine. Regular cleaning prevents the accumulation of dirt and slows down the oxidation process.

3. Dry Storage : Avoid contact with moisture and chemicals, and refrain from wearing silver jewelry while swimming, especially in the sea. Store silver jewelry in dry, sealed containers, protecting them from humid environments. Humidity is a major factor in silver jewelry oxidation. Avoid storing it alongside hairspray, perfume, or skincare products, as this could lead to a decrease in its luster.

4. Separate Storage : Try to prevent direct contact between silver jewelry and other pieces to avoid potential metal reactions and oxidation. Also, avoid wearing other precious metal jewelry simultaneously to prevent deformation or abrasion.

5. Anti-Oxidation Agents and Polishing Cloth : Use anti-oxidation products or dedicated polishing cloths to regularly care for your silver jewelry. These products can slow down oxidation and maintain the shine. Be sure to follow the instructions carefully.

Incorporating these tips into your silver jewelry care routine can help you enjoy your pieces for a long time without the worry of rapid oxidation.

I hope everyone can gain a deeper understanding of silver jewelry through this article. If you have any further questions about silver jewelry that you'd like to know, please feel free to contact us Jewel Bushra via email at any time!