How do jewellers get rings so shiny?

The two tools doing most of the work are ultrasonic cleaners and steam guns. An ultrasonic cleaner sits the ring in a warm soapy solution and pulses high-frequency sound waves through the liquid, which form and collapse microscopic bubbles against the metal. Each collapsing bubble releases a tiny shockwave that lifts dirt out of crevices a brush cannot reach. A steam gun then directs a jet of high-pressure dry steam at the ring to flush out everything the ultrasonic loosened. The combination clears residue that has built up for years in three or four minutes, which is why a ring back from the jeweller usually looks brighter than after any home clean.

Two things require an actual jeweller and cannot be replicated at home. A motorised polishing wheel with progressively finer compounds buffs out the fine surface scratches that build up on the band over years, restoring the original mirror finish. The wheel removes a few microns of metal each pass, which is why polishing is reserved for every few years rather than every visit. White gold rings also need a rhodium replate every two to five years, since the bright white finish is a thin plated layer over a slightly yellow base alloy and wears off with normal use. Both jobs run AU$100 to AU$300 depending on complexity, and both should be paired with a prong check while the ring is off the finger.