Most dullness is not tarnish. It is a film of soap, sunscreen, hand cream and skin oil sitting in the crevices where light should be bouncing. Removing it takes four minutes and nothing you do not already own.

The method

• Half a bowl of warm — not hot — water with two drops of plain dishwashing liquid.
• Soak for ten minutes. Longer for chains, which trap the most.
• Brush gently with a soft baby toothbrush, paying attention to the back of settings where light enters.
• Rinse in clean water. Put a strainer in the sink first — this advice has saved more rings than anything else here.
• Dry completely with a lint-free cloth before storing. Trapped moisture is what actually causes problems.

What to never do

Toothpaste is abrasive — it is designed to be. On gold it leaves a haze of microscopic scratches that dulls the finish permanently. Baking soda does the same. Bleach attacks the alloy metals in gold and will pit it.

Ultrasonic cleaners are excellent for plain gold and diamonds, and ruinous for almost everything else. Emeralds are commonly oil-treated and the vibration drives the oil out, leaving the stone visibly cloudy. Polki, kundan and any foil-backed setting can lift. Pearls and opals should never go near one.

Storage does more than cleaning

Gold scratches gold. Pieces stored loose together abrade each other every time the box moves. Individual soft pouches, chains fastened so they cannot knot, and a dry cupboard rather than a bathroom shelf will keep jewellery looking new far longer than any cleaning routine.