Jewellery Cleaning and Maintenance: The Complete Professional Guide

Clean jewellery is beautiful jewellery. Even the finest diamond looks flat and lifeless under a film of skin oils, soap residue, and everyday grime. A ruby that appears dull in morning light can be transformed in five minutes with the right cleaning technique. Yet cleaning — done incorrectly — is also one of the most common sources of gemstone damage. Ultrasonic cleaners fracture treated emeralds. Steam cleaners drive moisture into porous stones. Ammonia-based solutions bleach organic materials. The difference between restoring a piece to its full beauty and damaging it irreparably often comes down to whether the person cleaning it knows the rules.

This article provides a complete professional guide to jewellery cleaning and maintenance — the methods available, which stones are safe for which methods, and the practical protocols that protect both gems and customer relationships.

Why Jewellery Gets Dirty

Understanding why jewellery accumulates deposits helps determine the best cleaning approach. The primary sources of build-up are: skin oils and perspiration (which create a greasy film particularly behind stones and in prong areas), cosmetics and lotions (which form waxy or powdery deposits), soap and hard water minerals (which leave a dull grey film), and environmental dust and pollution (which settles in crevices and setting details).

The area behind a stone — between the pavilion and the setting — is particularly prone to build-up because it is rarely touched during regular wear and because oils wick into narrow spaces by capillary action. A diamond ring that looks dull usually looks stunning again immediately after professional cleaning that reaches this under-stone zone.

Cleaning Methods: From Safest to Most Powerful

Warm Soapy Water and Soft Brush

The safest and most universally applicable cleaning method is warm water with a small amount of mild, phosphate-free dish soap, applied with a soft-bristled brush (a baby toothbrush is ideal). This method is appropriate for almost all gemstones and metal types, removes the majority of everyday build-up, and carries virtually no risk of damage if done correctly.

Technique: place the piece in a small bowl of warm (not hot) soapy water and allow to soak for two to five minutes to loosen deposits. Use the soft brush to gently scrub all surfaces, paying particular attention to the under-stone area and around prongs. Rinse thoroughly under running warm water (with the drain covered or using a separate rinse bowl), and dry with a soft lint-free cloth or air dry.

Not appropriate for: pearls (soak weakens the silk cord and may damage nacre), turquoise and other porous stones (may absorb moisture), amber (prolonged soaking damages surface), and pieces with loose or damaged settings (soaking may displace stones).

Ammonia Solution

A dilute ammonia solution (one part ammonia to six parts water) cuts through grease and oil deposits very effectively and is particularly useful for diamonds set in gold or platinum. It was the basis of many commercial jewellery cleaners for decades.

Safe for: diamonds, rubies and sapphires (untreated), most hard gemstones with no fracture filling. Not safe for: pearls (ammonia attacks nacre), coral, amber, turquoise, opal, and any treated gemstone. Ammonia should never be mixed with bleach — this creates toxic chloramine gas.

Commercial Jewellery Cleaning Solutions

Commercial jewellery cleaners vary widely in their chemistry. Many are ammonia-based; others use surfactants and chelating agents. The safest approach is to check the product’s safety list for the specific stones in the piece. No commercial cleaner should be assumed safe for all gemstones — always verify, especially for pearls, emeralds, opal, and organic gems.

Steam Cleaning

Steam cleaning uses high-pressure steam to blast away deposits. It is highly effective for diamonds and hard, stable gemstones and is a standard tool in professional jewellery repair shops. The high temperature and pressure make it unsuitable for thermally sensitive gems (opal, tanzanite, emerald, amber, pearl, coral) and for pieces with loose settings.

Steam cleaning is safe for: diamonds in solid settings, hard unheated rubies and sapphires, spinel, and most garnets. Avoid for: all thermally sensitive stones, all treated stones (oil, resin, or glass fills), organic gems, and pieces with damaged or loose settings.

Ultrasonic Cleaning

Ultrasonic cleaners use high-frequency sound waves transmitted through a liquid to create microscopic cavitation bubbles that implode against surfaces, physically removing deposits. They are extremely effective for pieces with intricate settings and hard-to-reach deposits.

Safe for: hard, untreated, inclusion-free diamonds in secure settings; hard corundum (untreated) in secure settings. Unsafe for: treated emeralds (destroys fracture fill), opal, pearls, coral, turquoise, tanzanite, stones with surface-reaching fractures, any stone with loose or damaged settings, amber, and any organic material. When in doubt, use a soft brush instead.

Quick-Reference Cleaning Guide by Gem Type

Diamond (untreated): warm soapy water, ammonia solution, steam, ultrasonic — all safe

Ruby/Sapphire (untreated): warm soapy water, steam — safe; ultrasonic safe for unfractured stones

Emerald (any): warm soapy water only — no ultrasonic, no steam, no solvents

Tanzanite: warm soapy water only — no ultrasonic, no steam

Opal: barely damp soft cloth only — no soaking, no chemicals, no steam, no ultrasonic

Pearl: barely damp soft cloth — no soaking, no chemicals, no ultrasonic; wipe after every wear

Turquoise/Lapis: dry cloth — no water, no chemicals

Amber: soft dry cloth — no solvents, no prolonged water contact

Garnet (most): warm soapy water — safe; check individual species before ultrasonic

Tourmaline: warm soapy water — generally safe; ultrasonic caution for fractured stones

Professional Cleaning Services: When and Why

Home cleaning removes surface deposits but cannot address the under-stone build-up that accumulates over years in ring settings. Professional cleaning — using steam and ultrasonic equipment alongside a thorough inspection — restores pieces to near-original condition. More importantly, a professional cleaning appointment creates the opportunity for a setting inspection.

Prongs work-harden and become brittle over time; they can crack or break without warning, releasing the stone. A professional inspection every six to twelve months catches prong wear, loose settings, and beginning fractures before they become losses. Offering free or subsidised cleaning and inspection to jewellery customers is one of the highest-return customer relationship investments available to a retail store.

Key Takeaways

Warm soapy water with a soft brush is the safest universal cleaning method — appropriate for almost all gems.

Ultrasonic cleaners: safe for hard untreated gems in secure settings; dangerous for emeralds, opal, pearls, tanzanite, and treated stones.

Steam cleaning: effective for hard stable gems; dangerous for thermally sensitive stones and treated gems.

Pearls require a soft damp cloth after every wear — acids in perspiration slowly dissolve nacre.

Never use toothpaste — it is abrasive and will scratch most gem and metal surfaces.

Professional cleaning every 6–12 months combines restoration with inspection — and creates repeat customer visits.