Does 9ct Gold Tarnish? Causes, Prevention & Cleaning Guide
9ct Gold Tarnishing: An Overview
9ct gold is a popular choice for jewellery due to its durability and affordability, but many buyers wonder: does 9ct gold tarnish over time? While gold does not tarnish, 9ct gold contains alloy metals like copper, silver, and zinc, which can react to moisture, chemicals, and air, leading to discolouration. This guide explains why 9ct gold tarnishes, how to prevent it, and the best ways to clean it safely.
Jump to Section
- Does 9ct Gold Tarnish?
- Why Does Some 9ct Gold Look Dull or Darken Over Time?
- How to Prevent Tarnishing in 9ct Gold Jewellery
- Best Cleaning Methods for 9ct Gold
- Does Tarnish Mean It’s Fake?
- FAQs About 9ct Gold & Tarnishing
- Conclusion & Further Reading
Does 9ct Gold Tarnish?
Yes, 9ct gold can tarnish over time, but this is a natural reaction due to its alloy content. Since 9ct gold is only 37.5% pure gold, the remaining 62.5% consists of metals that can oxidize when exposed to air, moisture, and chemicals.
How Does Tarnishing Compare to Higher Karat Gold?
- 9ct gold tarnishes more than 18ct or 24ct gold because it contains more alloy metals.
- 18ct gold (75% pure gold) is less likely to tarnish but may still dull over time.
- 24ct gold (99.9% pure gold) does not tarnish, but it is too soft for everyday jewellery.
Hallmarking & Tarnish
Hallmarking is a legal requirement in the UK for precious metals like gold to ensure authenticity and protect consumers from fraud. The London Assay Office provides detailed guidelines on hallmarking standards, including those for 9ct gold (375 purity). Checking for a hallmark can help confirm that a piece is genuine and that any tarnishing is due to natural alloy oxidation rather than being fake.
Why Does Some 9ct Gold Look Dull or Darken Over Time?
Several factors cause 9ct gold to develop a dull or dark appearance:
- Exposure to Moisture & Humidity – Trapped moisture speeds up oxidation, causing dullness.
- Sweat & Skin Chemistry – Natural oils, salts, and acidity from your skin react with metals like copper and silver.
- Chemical Contact – Perfumes, lotions, chlorine, and cleaning agents can cause tarnishing.
- Sulfur & Pollution – Airborne sulfur (from pollution, rubber, and certain foods like eggs or onions) reacts with metals in gold, leading to a tarnished layer.
How to Prevent Tarnishing in 9ct Gold Jewellery
1. Store Jewellery Properly
- Keep in a dry, airtight container or a jewellery box with anti-tarnish strips.
- Avoid storing multiple pieces together to prevent scratches and metal reactions.
2. Minimize Exposure to Chemicals
- Apply lotions, perfumes, and sprays before putting on jewellery.
- Remove jewellery before swimming, showering, or using cleaning products.
3. Clean Jewellery Regularly
- Wipe your gold jewellery with a soft, dry cloth to remove oils and residue after each wear.
- Use a gentle gold-cleaning solution once a month for maintenance.
4. Wear It Regularly
Surprisingly, wearing 9ct gold often can slow tarnishing because the natural movement polishes the surface.
Best Cleaning Methods for 9ct Gold
1. Mild Soap & Warm Water (Best for Regular Cleaning)
- Mix warm water with mild dish soap.
- Soak the jewellery for 5–10 minutes.
- Gently scrub with a soft toothbrush.
- Rinse and dry with a lint-free cloth.
2. Baking Soda & Water Paste (For Light Tarnish)
- Mix baking soda with a few drops of water to form a paste.
- Apply gently with a soft cloth and rinse off.
3. Professional Cleaning & Polishing
Take the jewellery to a professional jeweller for ultrasonic or steam cleaning for heavy tarnish.
Does Tarnish Mean It’s Fake?
No, tarnish does not mean 9ct gold is fake. Tarnishing is a natural reaction in alloy-based gold due to moisture, chemicals, and oxygen exposure. Conversely, fake gold may show discolouration but react differently to hallmark tests and gold verification methods.
FAQs About 9ct Gold & Tarnishing
Does 9ct gold tarnish more than 18ct gold?
Yes, 9ct gold tarnishes faster because it has more alloy metals that react with air and moisture.
Can you reverse tarnishing on 9ct gold?
Yes, you can remove tarnish with proper cleaning methods, such as mild soap and water or a gold-polishing cloth.
Does sweat make 9ct gold tarnish faster?
Yes, sweat contains salts and acids that can accelerate oxidation and tarnishing.
Is white gold more prone to tarnishing?
White gold is rhodium-plated; when the coating wears off, it can look dull or slightly yellow. Replating is needed to restore its shine.
Conclusion & Further Reading
While 9ct gold can tarnish over time, proper care and storage can prevent discolouration and keep your jewellery looking its best. Regular cleaning and mindful wear will help maintain its shine and durability.