Why Costume Jewellery Tarnishes So Quickly

Costume jewellery is rarely made from solid silver or gold. Most pieces begin with a base metal — brass, copper, steel or a zinc alloy — which is then finished with an extremely thin layer of gold, rhodium, silver or coloured plating. That plating is measured in microns, and it is the plating that gives the piece its brightness. What most of us call tarnish is a film of sulphides and oxides that forms when the surface metal meets air, moisture and the natural oils on your skin. It shows up as a faint grey or yellowish bloom rather than a shine, and it often dulls first along the edges and the parts that sit against your skin.

It helps enormously to tell the difference between tarnish and wear. Tarnish sits on top of the metal and can usually be lifted away with gentle cleaning. Plating wear is different: it appears as flat, dull patches of grey, pink or greenish base metal, often on the raised points that rub against clothing or skin. No amount of polishing will bring plating back, and scrubbing at it will only spread the bare patches. If your piece has gone patchy rather than merely dull, clean it once, gently, and then treat it with care.

Start with Mild Soap and Warm Water

For the vast majority of costume pieces, the safest method is also the simplest. Warm water and a mild, non-acidic soap will lift surface tarnish and everyday grime without touching the plating underneath.

• Fill a small bowl with warm — not hot — water. Very hot water can soften adhesives and cloud some coatings or faux pearls.
• Add two or three drops of mild washing-up liquid, or use a gentle, unperfumed hand soap. Avoid anything containing lemon, vinegar, bleach or ammonia, and skip antibacterial washes, which can be harsh on delicate finishes.
• Line the bowl with a soft cloth so that if a stone or an earring back comes loose, it lands somewhere you can find it rather than in the plughole.
• Soak for around five minutes. Ten is the absolute maximum for a sturdy metal piece, and glued settings should be dipped rather than left to steep.
• Lift the piece out and work the suds around it with your fingertips, paying attention to the back and the clasp, where grime collects unnoticed.
• Rinse in a second bowl of clean, lukewarm water. Never hold a piece under a running tap with the plug out.

Choose the Right Brush and Handle Stones with Care

A brush is useful for textured metal and chain links, but the wrong one will scratch plating in seconds. Stay away from wire brushes, scouring pads and even firm nail brushes.

• Use a soft baby toothbrush or a clean make-up brush. A child's toothbrush has bristles soft enough for plated surfaces and small enough to reach into settings.
• Work on a folded towel so nothing rolls away, and hold the piece flat against the towel rather than in mid-air.
• Brush in small circles with light pressure. Let the bristles do the work — pressing harder does not clean better, it just thins the plating.
• For grime in tight crevices, wrap a wisp of cotton wool around a wooden cocktail stick and ease it along the recess.
• Support the setting with one finger while you clean around a stone. Glued crystals, faux pearls, resin and painted enamel should be cleaned with a damp cloth rather than soaked, as prolonged water contact softens adhesive and loosens settings.

Dry Carefully — This Is Where Most Damage Happens

Leaving a piece to air dry on a windowsill is one of the most common causes of repeat tarnish and lifted stones. Water trapped behind a stone or inside a hollow finding will sit there for hours, quietly doing damage.

• Pat the piece dry with a soft, lint-free cloth. Rubbing briskly can catch a claw or a glued stone and pull it free.
• Press the cloth gently around each stone to draw moisture out of the setting.
• Use a hairdryer on the cool setting, held at least a foot away, for thirty seconds or so. Warm or hot air can warp resin and loosen adhesive.
• Leave the piece on a dry towel for half an hour before putting it away, just to be certain.
• Finish with a light buff using a dry microfibre cloth. This removes any lingering water marks and restores a soft shine.
• Avoid kitchen paper and tissues — the wood fibres are surprisingly abrasive on plated metal.

Methods to Avoid on Plated Pieces

Plenty of popular cleaning tricks are designed for solid silver, and they are far too aggressive for costume jewellery. Skip all of the following:

• Silver dip and liquid tarnish removers. These dissolve metal, and on a plated piece they will take the plating with the tarnish.
• Baking soda and foil, vinegar, lemon juice or ketchup. All are acidic and will pit the surface and strip the finish.
• Toothpaste. It is a mild abrasive, and it will dull gold tone plating into a chalky mess.
• Ultrasonic cleaners. The vibration shakes stones out of settings and can lift plating at the edges.
• Ammonia, bleach, chlorine and acetone. These attack both the plating and any adhesives or coatings.
• Rouge polishing cloths intended for solid metals, which cut through thin finishes quickly.

If a piece is sentimental or you suspect it may be more valuable than it looks, a jeweller is the safer pair of hands.

Everyday Habits That Keep Tarnish at Bay

Prevention is far easier than restoration, and it costs nothing but a little order in your routine.

• Put jewellery on last, once perfume, hairspray, moisturiser and sunscreen have dried.
• Take it off before showering, swimming, washing up, exercising or going to bed.
• Wipe each piece with a dry soft cloth after wearing it, then store it straight away.
• Keep pieces in separate small pouches or a lined box so they do not rub against each other and wear away the plating at the contact points.
• Store in an airtight bag with a silica gel sachet where you can, and avoid the bathroom, whose damp air accelerates tarnish.

Follow those steps and most costume pieces will keep their brightness for years rather than months. When a favourite does start to dull, reach for warm water and mild soap first — it is almost always enough.