Why Silver Turns Black and How to Clean It
One of the most common questions about silver is: why does it turn black? And is black silver still real silver? The answers involve some fascinating chemistry — and the good news is that tarnished silver can almost always be restored to its original shine.
The Science of Silver Tarnishing
Silver turns black due to a chemical reaction called tarnishing. When silver is exposed to air, it reacts with hydrogen sulphide (H₂S) — a sulphur compound present in small amounts in the atmosphere. This reaction produces silver sulphide (Ag₂S), which is black.
The reaction is: 4Ag + 2H₂S + O₂ → 2Ag₂S + 2H₂O
Silver sulphide forms a thin layer on the surface of the silver, creating the dark appearance. This is not damage — the silver underneath is untouched. Tarnish is purely a surface phenomenon.
Is Tarnished Silver Still Pure?
Yes, absolutely. Tarnishing is actually a sign that your silver is genuine. Base metals, plated silver, and German silver do not tarnish in the same way as pure silver. If your silver article tarnishes evenly and can be polished back to bright silver, it is a good sign of authenticity.
What Speeds Up Tarnishing?
- Humidity — the most significant factor; moisture accelerates the reaction
- Air pollution — cities have more sulphur compounds in the air
- Perfumes and cosmetics — contain sulphur compounds
- Rubber — contains sulphur; never wrap silver in rubber bands
- Eggs, onions, mustard — these foods release sulphur when cooked
- Wool fabrics — contain sulphur compounds
- Chlorine — swimming pools accelerate tarnishing
Why Does Some Silver Turn Yellow?
Sometimes silver develops a yellow or orange tint rather than black. This is usually due to copper oxidation (silver alloys contain 7.5% copper) or reaction with certain chemicals. Yellow tarnish is treated the same way as black tarnish — with any standard silver cleaning method.
5 Methods to Clean Tarnished Silver
Method 1: Silver Polishing Cloth
Best for: Regular maintenance and light tarnish Gently rub the tarnished surface with the polishing side of a silver cloth. Then buff with the clean side. Takes 2-3 minutes. Keep one in your puja ghar for monthly maintenance.
Method 2: Toothpaste
Best for: Moderate tarnish on smooth surfaces Apply a small amount of non-gel white toothpaste to a soft cloth or old toothbrush. Rub gently in circular motions. Rinse with lukewarm water and dry immediately. The mild abrasive in toothpaste removes tarnish effectively.
Method 3: Baking Soda + Aluminium Foil
Best for: Heavy tarnish, the best home method for severely tarnished pieces Line a bowl with aluminium foil (shiny side up). Add hot water and 1 tablespoon of baking soda per litre of water. Place the silver article in the solution for 5-10 minutes. The tarnish transfers electrochemically to the aluminium. Remove, rinse, and dry.
Method 4: Lemon Juice and Salt
Best for: Light tarnish, especially on heavily engraved pieces Mix fresh lemon juice with a small amount of salt. Apply with a soft cloth, leave for 2 minutes, rinse quickly with water, and dry. Do not leave acidic solutions on silver for too long.
Method 5: Commercial Silver Cleaner
Best for: Heavily tarnished silver, professional results Available at jewellers and hardware stores. Follow the instructions carefully. Good commercial cleaners are effective and gentle.
What NOT to Do
- Never use bleach or ammonia — they can permanently damage silver
- Never put silver in a dishwasher — the harsh detergents and heat are damaging
- Avoid steel wool or abrasive pads — they will scratch the surface
- Do not leave water or cleaning solutions on silver for too long
Preventing Tarnish Long-Term
- Store in anti-tarnish cloth pouches
- Place silica gel in your silver cabinet
- Add chalk or activated charcoal to absorb sulphur
- Wipe silver dry after every use
- Keep away from rubber, wool, and chemicals
At Faincy Silver in Jaipur, we offer professional re-polishing services for tarnished articles — restoring pieces to their original glory, no matter how badly tarnished.