Caring for Pearl and Opal Jewellery: The Complete Guide

Pearl and opal jewellery is as beautiful as it is unforgiving. Both materials are organic or semi-organic (opal contains water), both are soft by gemstone standards, and both are damaged by the chemicals found in everyday products that a diamond or sapphire would not notice. The knowledge gap between "how to look after a diamond" and "how to look after a pearl" is enormous — and that gap costs people money every year in restringing, re-polishing, and in some cases, replaced stones.

Understanding what pearls and opals actually are

Pearls are formed from calcium carbonate (aragonite) secreted by a mollusc around an irritant. They consist of layered nacre — the same iridescent material that lines the shell's interior. The nacre layers are thin, stacked, and relatively soft (Mohs 2.5–4.5). The lustre that makes pearls beautiful is a product of light diffracting through those layers. Anything that damages or thickens those layers — acids, abrasives, dehydration — diminishes the lustre.

Opals are formed from silica gel that solidified over millions of years, trapping tiny spheres of silica in a regular matrix. The spectral colour play (the "fire") comes from diffraction through that matrix. Crucially, opals contain 6–10% water by weight. Extreme drying conditions can cause crazing — networks of fine internal cracks — and thermal shock can crack them outright.

Daily wear rules for pearls

Put them on last, take them off first. This is the single most important rule. Perfume, hairspray, hand cream, makeup — all applied before putting on pearl jewellery — contain alcohols and acids that attack nacre on contact. Apply everything first, allow it to dry and absorb, then put the pearls on.

Wipe after each wear. A clean, damp chamois or soft microfibre cloth wiped gently over each pearl before storage removes skin acids and perspiration before they can act on the nacre overnight. This takes thirty seconds and extends the pearl's life significantly.

Never shower or swim in pearls. Repeated wetting and drying of the silk thread accelerates degradation. Pool chlorine attacks nacre. Salt water from the sea is equally damaging.

Daily wear rules for opals

Avoid thermal shock. Going from a cold Scottish day into a heated car or warm building rapidly is not in itself a problem for an opal. What is dangerous is a sharp local temperature change — placing an opal under boiling water, or leaving it on a sunny windowsill in direct summer sun. Keep opals away from direct heat.

No ultrasonic cleaning, ever. The ultrasonic vibrations that safely clean a diamond can crack an opal from within. This is not a theoretical risk — it happens. If an opal piece needs professional cleaning, tell the jeweller what it is before leaving it.

Protective settings for opal rings. If you wear an opal ring, the setting matters greatly. A bezel setting (where a rim of metal wraps around the stone's edge) provides far more protection from knocks than a claw setting. For daily-wear opal rings, a bezel or partial bezel in 18ct yellow gold (softer, less likely to crack the stone during setting) is our recommendation.

Cleaning pearls safely

There is no shortcut to cleaning pearls safely — no chemical solution, no machine, no steam. The method is:

1. Dampen a very soft cloth (chamois or microfibre) with clean, room-temperature water. Add one very small drop of unscented, neutral pH soap if needed.
2. Wipe each pearl gently, one at a time, with a rotating motion.
3. Follow immediately with a dry section of the cloth.
4. Lay the strand flat on a dry towel — never hang it to dry (wet silk stretches under the weight of the pearls).
5. Allow to dry completely in open air before storing.

If the pearls look dull despite cleaning, the nacre surface may have picked up fine scratches from abrasive contact. A professional re-polishing of pearl surfaces is sometimes possible on higher-quality cultured and natural pearls — ask us to assess them.

When to re-string a pearl strand

A pearl strand should be restrung when:

• You can see slack between the knots (the knots have migrated, indicating silk stretch)
• The silk has discoloured — yellow, grey or brown tones mean the silk has absorbed skin acids
• Any knot shows fraying
• The strand is more than three years old and worn regularly
• It has been soaked or badly wet at any point

We re-string pearl necklaces in the workshop using silk thread knotted between each pearl in the traditional manner. The cost is from £40 for a 16-inch single strand; longer or multi-strand necklaces are quoted individually. We match the thread colour exactly and can replace the clasp at the same time.

Come in to 7 Murray Place, Stirling, any day Mon–Sat 09:30–17:00, and we'll assess your strand for free.