Gold, in its purest form (24 karats), is a chemically inert metal, meaning it does not react with oxygen or most other chemicals and, thus, doesn't tarnish. However, pure gold is also soft and isn't typically used for everyday jewelry because it can scratch and bend easily. That's why pure gold is often alloyed (mixed) with other metals to increase its strength and durability.

18k Gold is 75% pure gold and 25% alloyed metals. The specific metals alloyed with gold can vary but commonly include copper, silver, zinc, and nickel. It is these alloyed metals that can sometimes react with the environment and lead to tarnish.

What Causes 18k Gold to Tarnish?

1. Composition of the Alloy: The mix of metals in 18k gold plays a pivotal role in its susceptibility to tarnishing.

  • Alloy Metals: While gold itself is resistant to tarnish, the metals alloyed with it can react with environmental factors and tarnish. Copper, for instance, oxidizes over time, especially when exposed to moist air. This leads to the formation of a greenish layer called patina. Silver, another common alloy, can sulfide and produce a black tarnish.
  • Purity Level: Higher karat gold, like 24k, contains more gold and less alloy, making it less prone to tarnishing than lower karat gold. However, the higher karat gold is also softer, making it less ideal for everyday wear.

2. Environmental Factors: Your surroundings can significantly impact the lifespan and shine of your gold jewelry.

  • Chemical Exposure: Chemicals in household cleaners, pools, and even air pollution can expedite the tarnishing process. Chlorine, in particular, is a harsh chemical that can weaken gold's structure and its alloys, making it more vulnerable to tarnishing.
  • Humidity & Air Quality: Living in regions with high humidity or poor air quality can lead to quicker tarnishing. Moist air provides an ideal environment for metals like copper and silver to oxidize or sulfide.

3. Personal Factors: Our bodies have unique chemistries that can influence how jewelry reacts over time.

  • Skin pH: Some people have more acidic sweat, which can cause a quicker reaction with alloy metals in gold, leading to tarnishing. On the other hand, individuals with more alkaline skin might not experience tarnishing as rapidly.
  • Personal Care Products: Deodorants, perfumes, and lotions might contain chemicals that can react with gold alloys, leading to tarnish. It's always advisable to wear jewelry after you've applied and allowed these products to dry.

4. Wear and Care: The frequency and conditions under which you wear your jewelry can greatly impact its appearance over time.

    • Skin Oils & Sweat: These natural body secretions can accumulate on the surface of your jewelry. Over time, these can react with the metals in the alloy, potentially speeding up the tarnishing process.
    • Friction: Constant contact with clothing, especially abrasive materials, can lead to minor surface scratches. While these don't directly cause tarnishing, they can make the gold more susceptible to external factors that do.
    • Direct Sunlight: Prolonged exposure to direct sunlight can accelerate the tarnishing process, especially if the gold alloy contains metals sensitive to UV light.
    • Cosmetic Products: Products like perfumes, lotions, and makeup often contain chemicals that can react with the metals in 18k gold, leading to quicker tarnishing. It's advisable to put on your jewelry after applying cosmetics and allowing them to dry.
    • Infrequent Cleaning: If 18k gold jewelry is not cleaned regularly, dirt and contaminants can accumulate on its surface. Over time, this can lead to a dull appearance and may accelerate tarnishing.
    • Improper Storage: When not wearing your jewelry, the way you store your jewelry plays a role in its maintenance. Tossing it haphazardly into a jewelry box can lead to scratches while keeping it in a humid environment can promote tarnishing.
    • Physical Activities: Wearing 18k gold jewelry during activities like exercising, gardening, or even doing household chores exposes it to sweat, dirt, and chemicals, all of which can contribute to tarnishing over time.

Preventing and Caring for Tarnished 18k Gold – Detailed Guide:

1. Regular Cleaning: Gold, although resistant to tarnish, can still accumulate dirt, grime, and oils from our skin, which can dull its shine over time.

  • Mild Soap and Lukewarm Water: This simple solution is effective for gently lifting dirt and oils without damaging the gold. Avoid hot water as it can cause gold to expand and misshape, especially if it's a delicate piece or contains gemstones.
  • Soft Cloth or Gentle Toothbrush: These tools are excellent for cleaning jewelry because they won't scratch the surface. For pieces with intricate designs, a toothbrush can get into the nooks and crannies. Always use back-and-forth motions, not circular, as circular motions can magnify any existing scratches.
  • Rinsing and Drying: Ensure all soap residue is thoroughly rinsed off, and pat dry using a lint-free cloth. Air drying can leave water spots, so it's best to manually dry your pieces.

2. Storage: Storing your jewelry correctly can prevent many issues before they start.

  • Dry Place: Humidity can be a contributing factor to tarnishing, so keeping your jewelry in a dry environment is key.
  • Individual Soft Pouches: These prevent pieces from scratching against each other. They also protect gold from dust and direct exposure to the atmosphere, which can reduce the risk of tarnishing.

3. Avoid Harmful Chemicals: Gold's luster can be affected by various chemicals, leading to discoloration and damage.

  • Chlorinated Water: Chlorine can react with gold, especially at high temperatures like in hot tubs, causing discoloration and even structural damage over time.
  • Chemicals and Cleaners: Household cleaners, perfumes, cosmetics, and even lotions can contain chemicals that might tarnish or damage gold. It's a good practice to put on your gold jewelry last when getting ready and to remove it first when coming home.

4. Professional Cleaning: Despite our best efforts, sometimes our jewelry needs a deep clean or check-up.

  • Deep Cleaning: Professionals use ultrasonic cleaners that send vibrations through a liquid solution, dislodging dirt and debris even from hard-to-reach places.
  • Inspection: Alongside cleaning, jewelers can inspect your jewelry for signs of wear, loose gemstones, or potential damage, ensuring the longevity of your piece.
  • Special Treatments: Sometimes, a piece might need polishing, re-plating, or other treatments to restore its original luster and shine.

5. Polishing: Gold, being soft, is prone to minor surface scratches over time, especially on pieces that are worn daily.

  • Gold Polishing Cloth: These cloths are infused with cleaning agents that safely buff out superficial scratches and restore the shine to gold. They're typically non-abrasive and chemically treated to clean and polish gold jewelry. Always follow the grain of the gold to avoid creating more scratches.
  • Frequency: While these cloths are gentle, it's best not to over-polish. Using a gold polishing cloth once a month or when you notice your jewelry losing its shine is generally enough.

6. Humidity Control: Be careful; gold can still lose its luster in high humidity.

  • Silica Gel Packets: These small packets, often found in new shoe boxes or with new electronics, are excellent for absorbing excess moisture in a confined space, like a jewelry box.
  • Placement: Place one or two packets in your jewelry box, and replace them once they're saturated (they typically turn color, like from orange to green, when they're full).

7. Promptly Address Spills: Accidents happen, and sometimes jewelry comes in contact with substances it shouldn't.

  • Immediate Cleaning: Rinse your gold jewelry in lukewarm water and pat dry if it comes in contact with acidic or harmful substances. Acidic substances can affect gold's shine and even its structural integrity over time.
  • Regular Inspection: After cleaning, always inspect your jewelry for any discolorations or potential damages.

8. Avoid UV Light: Extended exposure to direct sunlight and UV light can accelerate the discoloration process of some metals mixed with gold.

  • Storage: When not in use, store your gold jewelry away from direct sunlight.
  • Outdoor Wear: If wearing gold jewelry outdoors for extended periods, consider covering it under clothing or wearing a hat to shield necklaces and earrings from direct sunlight.

9. Avoid Pollution: Air pollutants can react with gold jewelry and the metals mixed with it.

  • Urban Areas: If you live in a city with high pollution levels, it might be a good idea to clean your jewelry more regularly.
  • Avoid Direct Contact: If you're in an area where the air is dense with smoke or other pollutants, consider removing your jewelry or covering it to minimize direct exposure.


18k gold, a blend of pure gold and other metals, possesses a magnificent allure that's cherished worldwide. While it boasts a higher resistance to tarnishing compared to lower-karat gold, its exposure to various environmental and personal factors can diminish its brilliance over time. By understanding these influencing factors and employing the recommended care and preventive measures, you can ensure that your treasured 18k gold jewelry retains its radiance and remains a source of pride for many years. Whether it's regular cleaning, avoiding harmful elements, or seeking professional assistance, a proactive approach will undeniably prolong the life and beauty of your golden keepsakes.