How to clean pearls: 5 gentle steps to keep a pearl necklace lustrous

Grandmother's necklace, the earrings from your wedding day: pearls often stay with people for a lifetime. All the more annoying when their lustre fades or the thread turns grey. When it comes to how to clean pearls, restraint is the key skill, because what gold or silver takes in its stride can damage a pearl for good.

The good news: the right care is simple and only takes a few minutes. These five steps show how to keep them clean gently, protect the delicate silk thread and store your necklace so it stays beautiful for a long time.

Why pearls are so delicate

Pearls are not stones: they grow inside molluscs. They are made of countless thin layers of nacre, a combination of calcium carbonate and organic protein. These layers create their typical lustre, but they are soft and react to acids, chemicals, heat and dryness. This applies to saltwater cultured pearls just as much as to freshwater ones.

Then there is the thread: necklaces are usually strung on silk. Silk stretches when wet, absorbs dirt and becomes brittle over time. The small knots between the beads stop them rubbing against each other and prevent them all from rolling away if the thread breaks.

Imitations made of glass or plastic with a pearly coating need the same gentle care, as the coating can peel off. Our guide on how to clean costume jewellery explains more.

1. Wipe gently after every wear

The most important care is also the simplest: after wearing them, wipe your pearls with a soft, lint-free cloth lightly moistened with clean water. This removes sweat, skin oils and perfume residue before they attack the nacre.

Roll each bead between your fingers so you wipe all the way round. Then go over the strand with a dry cloth and let it lie flat for a moment before putting it away.

2. A deeper clean with mild soapy water

If a necklace looks dull despite regular wiping, give it a more thorough clean – but without a bath:

1. Mix lukewarm water with a drop of mild soap without additives, such as pure curd soap.
2. Dip a soft cloth in the water and wring it out very well.
3. Wipe each bead individually, including around the knots.
4. Wipe again with a second cloth dampened with clean water only.
5. Pat dry and let the necklace dry lying flat on a towel until the thread is completely dry, ideally overnight.

Not every household remedy is suitable: vinegar, citric acid and lemon juice are among the products that the Swiss consumer protection foundation recommends instead of many cleaning agents, but they have no place on pearls. Acid dissolves the calcium carbonate in the nacre, and baking soda paste acts like a scouring agent.

3. Keep an eye on the thread and clasp

The silk thread is the weak link in every necklace. So never wear it wet and don't hang it up to dry: the weight of the beads stretches the damp thread.

Have your necklace restrung by a jeweller as soon as you notice any of these signs:

• Visible gaps appear between the beads and the knots.
• The thread is grey, discoloured or frayed.
• The clasp is loose or no longer closes securely.

Depending on how often you wear the necklace, this will be due every few years. Clean a gold or silver clasp only with a soft, dry cloth. The necklace must never go into a silver dip; for silver pieces without pearls, see our guide on how to clean silver.

4. No chemicals, no ultrasound, no heat

Many methods that work on other jewellery are off-limits here:

• Ultrasonic and steam cleaners: vibration and heat can crack the nacre or make it flake.
• Jewellery cleaners and dips: they often contain acids or other substances that destroy the lustre.
• Alcohol, bleach, ammonia, acetone: they attack the nacre and the thread.
• Toothpaste, cream cleansers, baking soda paste: they scratch the soft surface.
• Hairdryers, radiators, direct sunlight: they dry the beads out.

Rings set with pearls should also be cleaned with a damp cloth only; for the gold setting, see our guide on how to clean gold jewellery.

5. Store pearls properly

Pearls are softer than almost any other jewellery. Keep them separately in a soft fabric pouch or a padded compartment so that gold, gemstones or clasps can't scratch them.

• Flat: hanging stretches the thread over time.
• Not airtight: plastic bags are unsuitable for long-term storage, because the nacre needs a little humidity.
• Protected: away from radiators, not on a sunny windowsill and not in the bathroom, where hairspray and perfume hang in the air.

Common mistakes when cleaning pearls

• Soaking: water gets into the drill hole, and the thread stretches and stains.
• Acidic home remedies: vinegar and lemon dull the nacre.
• Tossing them in with other jewellery: scratches are inevitable.
• Hanging the necklace: the silk thread gives way over time.
• Putting off restringing: if the thread breaks, beads are quickly lost.

Priority Clean editorial teamOur cleaning team from Alberswil, Canton of Lucerne, shares hands-on experience from move-out, house, office and window cleaning across Central and Northwestern Switzerland.