How To Clean Metal Detecting Finds and Preserve Them Without Damaging Them – Coins, Relics, and Jewellery

Every detectorist knows the rush of pulling a find from the soil. Whether it’s a worn Georgian penny, a twisted medieval buckle, or a silver ring glinting in the sunlight, each discovery carries centuries of history.

But what you do after finding it is just as important as the discovery itself. Cleaning and preserving your finds improperly can strip away valuable details, destroy patina, or even reduce legal and financial value.

This guide will show you safe, proven methods to clean metal detecting finds and preserving coins, relics, and jewellery found while metal detecting in the UK – ensuring they stay protected for years to come.

Why Proper Cleaning and Preservation Matters

• Historical value – A corroded coin might still carry inscriptions that tell its story. Scrubbing too hard could erase them.

• Legal reporting – Under the UK’s Treasure Act and PAS (Portable Antiquities Scheme), condition matters for recording. Cleaning incorrectly may affect classification.

• Market value – Collectors often prefer coins with natural patina. Over-cleaning can dramatically reduce worth.

• Longevity – Proper preservation prevents further corrosion, especially with metals like copper and iron.

General Principles Before You Clean Your Metal Detecting Finds

1. Do no harm first – Less is more. Over-cleaning is irreversible.

2. Identify before cleaning – If you suspect an item is rare or valuable, consult the PAS or a finds liaison officer (FLO) before touching it.

3. Avoid harsh chemicals – Household cleaners, vinegar, and wire brushes are disastrous for most finds.

4. Always document finds before cleaning – Photograph items as they come out of the ground for recording.

Basic Tools for Cleaning Finds

• Soft toothbrush

• Distilled water (tap water can contain minerals)

• Cotton buds / microfibre cloth

• Wooden cocktail sticks or toothpicks

• Soft rubber erasers (for light surface dirt)

• Acetone (for removing modern adhesive or tape, safe on many metals)

• Conservation-grade microcrystalline wax (e.g., Renaissance Wax)

Optional specialist tools:

• Ultrasonic cleaner (for modern jewellery, not ancient coins)

• Compressed air blower

• Soft brass brush (only for modern, robust coins like pennies)

Cleaning Coins

Coins are the most common finds in the UK. Their cleaning needs vary depending on metal type and condition.

Copper and Bronze Coins

• Best practice: Light cleaning only. The patina (green/brown surface) protects the coin.

• Method:

  1. Rinse gently in distilled water.

  2. Use a soft toothbrush to remove loose soil.

  3. For stubborn dirt, soak in distilled water for a few days, changing daily.

  4. Use a wooden toothpick to tease away deposits if necessary.

Avoid: Vinegar, lemon juice, baking soda, or abrasives – they strip patina.

Silver Coins

• Best practice: More resilient than copper, but tarnish and soil should still be treated carefully.

• Method:

  1. Rinse in distilled water.

  2. For light tarnish, gently rub with a soft cloth.

  3. For heavier soil, a mild soap solution (non-abrasive, pH neutral) may be used.

  4. Dry immediately to avoid water marks.

Note: Silver coins with black sulphide toning should often be left as-is, as collectors value natural toning.

Gold Coins

• Best practice: Gold does not corrode, making it the easiest metal to clean.

• Method:

  1. Rinse in warm distilled water.

  2. Gently rub with a soft cloth or cotton bud.

  3. Soap solution if needed.

Avoid: Strong chemicals – unnecessary for gold.

Iron Coins (rare, mostly tokens or very old issues)

• Best practice: Usually too fragile to clean mechanically.

• Method:

  • Stabilise with controlled drying.

  • Apply microcrystalline wax for protection.

Preserving Coins

• Storage: Acid-free coin envelopes, flips, or trays. Avoid PVC, which releases chemicals.

• Labelling: Always record date, location, and context.

• Protection: Apply a thin coat of Renaissance Wax for long-term conservation.

Cleaning Relics

Relics range from buckles and buttons to tools, weapons, and religious artefacts. Each material requires care.

Iron Relics

Iron is notorious for corrosion.

• Method:

  1. Dry completely to stop active rust.

  2. Brush gently with a soft brass brush to remove loose rust.

  3. Stabilise with tannic acid or rust converters (museum-grade products).

  4. Seal with Renaissance Wax.

Warning: Electrolysis is sometimes used but can be too aggressive if not done by experts.

Bronze Relics

• Method:

  • Rinse in distilled water.

  • Carefully pick soil with a wooden tool.

  • Avoid removing stable patina.

Preservation: Waxing helps protect against future corrosion.

Lead Relics

• Method:

  • Rinse gently in distilled water only.

  • Do not scrub – lead is soft and scratches easily.

  • Store in dry conditions, as damp causes lead rot.

Pewter and Tin Relics

• Method:

  • Extremely fragile – clean only with distilled water and soft cloth.

  • Avoid soaps and chemicals.

Bone, Leather, and Organic Relics

If you uncover organic relics (bone, leather, wood), avoid cleaning in the field. These require specialist conservation – contact PAS or a museum immediately.

Cleaning Jewellery

Jewellery, whether modern or ancient, requires tailored cleaning.

Gold Jewellery

• Method:

  • Rinse in warm distilled water.

  • Use mild soap if needed.

  • Polish lightly with soft cloth.

Silver Jewellery

• Method:

  • Clean as with silver coins.

  • For tarnished modern silver, silver polishing cloths can be used.

  • For ancient silver, leave toning intact.

Gemstones

• Method:

  • Rinse in warm distilled water.

  • Avoid ultrasonic cleaners for fragile or antique stones.

  • Never use chemicals.

Costume Jewellery (brass, plated, glass)

• Method:

  • Clean gently with water and cloth.

  • Plated surfaces can wear easily, so avoid rubbing.

Preserving Finds

After cleaning, preservation is critical:

1. Drying – Ensure all moisture is removed to prevent corrosion.

2. Waxing – Apply Renaissance Wax to metals for a protective barrier.

3. Storage Environment – Keep in stable temperature and humidity. Avoid damp sheds or attics.

4. Display – Use acid-free mounts or cases. Avoid adhesives directly on finds.

Legal and Ethical Considerations in the UK

• Treasure Act – If your find qualifies as treasure, report it. Cleaning is discouraged until recording.

• Portable Antiquities Scheme (PAS) – For non-treasure finds, FLOs can advise on cleaning and conservation.

• Ethics – Over-cleaning removes historical data. Responsible detectorists preserve the past, not polish it away.

Mistakes to Avoid

• Using wire brushes on coins.

• Soaking copper in vinegar or cola.

• Polishing ancient silver with chemical dips.

• Storing finds in PVC coin flips.

• Ignoring corrosion – it spreads if untreated.

FAQs

Should I clean all my finds? No – sometimes “as found” condition is best, especially for coins.

What’s the safest one-size-fits-all method? Gentle rinsing with distilled water, followed by drying.

Can I use olive oil to soak coins? A traditional method, but modern conservation discourages it – it darkens coins and can be hard to reverse.

What if I find something rare? Contact your FLO before cleaning.

Conclusion

Cleaning and preserving your finds is as important as discovering them. Every coin, relic, and piece of jewellery tells a story – and heavy-handed cleaning risks silencing that story forever.

By following conservation-friendly methods, using distilled water, soft tools, and microcrystalline wax, you’ll ensure your finds survive for study, enjoyment, and future generations.

Remember: as detectorists, we’re not just treasure hunters. We’re caretakers of history.