Why Pearls Dull Over Time

Pearls are unlike any other gem you will ever own. They are not cut from stone but grown layer by layer inside a living mollusc, and that layered coating — the nacre — is what gives them their soft, deep glow. It is also remarkably delicate. At around 2.5 to 3 on the Mohs scale, nacre is softer than a fingernail, and it reacts badly to acid, alcohol and abrasives.

Everyday wear dulls a pearl in predictable ways. Natural skin oils, hand cream and sunscreen sit on the surface and trap dust. Perfume, hairspray and cosmetics contain alcohols and acids that slowly etch the nacre, leaving it chalky rather than luminous. Silk thread, storage pouches and dry air pull moisture out of the pearl, which makes it look flat and lifeless. The good news is that most of this is reversible. A pearl that looks tired is usually just dirty or thirsty — not damaged beyond saving.

What You Will Need

You probably already own everything necessary, and that is the point. Harsh commercial cleaners are the enemy here, so simple is genuinely better.

• A bowl of lukewarm water — comfortably warm to the touch, never hot
• A drop of mild soap: baby shampoo, pure castile soap or a gentle pH-neutral hand wash
• Two soft cloths, ideally lint-free microfibre or clean cotton. A spare silk scarf works beautifully
• A soft-bristled makeup brush for textured or carved settings, if needed
• A dry towel to rest pieces on while you work

That is the entire kit. Steer away from washing-up liquid, which is far too degreasing, and from anything labelled "jewellery cleaner" unless it specifically states it is safe for pearls.

A Gentle Step-by-Step Clean

Work over a towel, and keep the bowl shallow so nothing can tumble and crack against the sides. Add one small drop of soap to the lukewarm water and swirl it until it is barely cloudy — you want a whisper of soap, not a lather.

Dip your cloth into the water, wring it out so it is damp rather than dripping, and wipe each pearl slowly. Use your fingertips to hold the piece steady. Work around the whole surface, including the sides where the silk passes through. Do not scrub. Pearls reward patience and punish pressure.

Rinse the cloth in clean lukewarm water, wring it out again, and wipe the soap residue away. Then pat — do not rub — the pearls dry with your second cloth, and leave them to air for an hour on a soft towel before wearing or storing. Never leave a pearl soaking. Nacre is porous, and prolonged immersion softens the surface and weakens the silk thread holding any strand together.

Techniques for Different Pieces

• Strung strands and necklaces: wipe rather than immerse. If the silk is badly discoloured, the honest answer is that the strand needs re-stringing, not a deeper clean. Most well-worn necklaces benefit from fresh knotting every one to two years.
• Stud earrings and pendants: these can be cleaned with a slightly dampened cloth pressed against the pearl, avoiding the metal fitting. Avoid soaking the glue or peg holding the pearl in place.
• Pearl rings and bracelets: these collect the most grime, so clean them more often. Use a faintly dampened cloth rather than a bowl, and take particular care around claw settings, where a soft brush helps loosen trapped cream and dust.
• Baroque and textured pearls: use a soft makeup brush dipped in the soapy water to reach into the ridges, then rinse with a clean, damp cloth.

What to Avoid

There is a long list of things that will strip a pearl's lustre permanently, and knowing them matters more than any cleaning method.

• Never use vinegar, lemon juice, bicarbonate of soda or toothpaste — all are acidic or abrasive and will eat into the nacre
• Never use ultrasonic cleaners or steam cleaners, however convenient they seem
• Avoid ammonia-based solutions, alcohol, bleach and any product containing them
• Avoid hard water, which leaves mineral deposits that cloud the surface
• Avoid brushing with anything stiffer than a makeup brush
• Avoid hot water, which can dry and crack the nacre

Protecting the Lustre Between Cleans

The simplest way to keep pearls glowing is to think about when you put them on. Make them the last thing you wear and the first thing you take off. That single habit keeps perfume, hairspray and moisturiser off the surface entirely, and it will do more for your pearls than any cleaning routine.

After wearing, wipe them gently with a soft dry cloth before putting them away — it takes ten seconds and removes the day's oils. Store them in a soft pouch or a fabric-lined compartment, away from harder gemstones that could scratch the nacre, and never in an airtight plastic bag. Pearls need a little moisture from the air to stay luminous. A dry, centrally heated room is the enemy, so keep them in a drawer rather than on a windowsill or radiator shelf.

Worn often, cared for gently and cleaned with nothing more aggressive than lukewarm water and a touch of mild soap, pearls will hold their glow for decades. Treat them as the living, breathing gems they are, and they will give that soft, unmistakable lustre back to you every time you wear them.