In this guide
Two questions come up constantly at our counter: how do I know this gold is real? and how do I get it looking new again?
This guide answers both — starting with something most articles on the subject will not tell you.
The honest answer about home testing
You will find plenty of pages listing home tests for gold purity. Here is the part they tend to skip: none of them can tell you whether a piece is 22K or 18K.
Home tests can sometimes flag a crude fake — a brass chain, a plated bangle. What they cannot do is measure purity. The difference between 916 and 750 gold is invisible, weighs almost the same, and behaves identically in every kitchen-table test ever devised. And since virtually all gold sold dishonestly in India is *under-karated* rather than outright fake, that is precisely the thing that matters.
The short version
Use home tests to satisfy curiosity about an unmarked heirloom. Use the BIS hallmark and HUID, or an XRF test at a jeweller, when the answer actually matters.
The home tests, and what each proves
The magnet test
What to do: hold a strong magnet near the piece.
What it means: gold is not magnetic. Strong attraction means significant iron or nickel content — a bad sign.
Its limitation: brass, copper and lead are not magnetic either. Passing this test tells you almost nothing. Clasps and springs often contain steel legitimately, so a slight tug at the clasp is normal.
The water displacement test
What to do: weigh the piece, then measure the water it displaces. Density = weight ÷ volume. Pure gold is about 19.3 g/cm³; 22K around 17.7.
What it means: a density far below those figures suggests a lighter metal inside.
Its limitation: you need accurate scales and precise volume measurement, hollow pieces and stones destroy the calculation entirely, and the gap between 22K and 18K is too small to resolve at home.
The ceramic scratch test
What to do: drag the piece lightly across unglazed ceramic.
What it means: gold leaves a gold-coloured streak; many fakes leave a black one.
Its limitation: it scratches your jewellery. We would not do this to a piece we cared about, and a gold-plated item passes it easily.
The vinegar test
What to do: a few drops of white vinegar on an inconspicuous spot.
What it means: gold does not react; some base metals discolour.
Its limitation: weak acid, weak evidence. It will not touch a plated piece and cannot grade purity.
The skin discolouration test
What to do: notice whether the piece leaves a green or black mark on your skin.
What it means: heavy alloying, or a plated base metal reacting with sweat.
Its limitation: genuine 22K can occasionally mark skin depending on body chemistry, cosmetics and humidity. Indicative at best.
The two methods that actually work
1. Verify the BIS hallmark — free, and takes a minute
Every hallmarked gold item sold in India carries the BIS mark, the purity grade (such as 22K916) and a six-character HUID. Download the free BIS Care app, enter the HUID, and the app returns the registered purity and the hallmarking centre that tested the piece.
If those details do not match what you hold, that is a genuine problem worth raising with the seller. Our hallmarking guide walks through reading the marks in detail.
2. Have it XRF tested
For unmarked or inherited gold, an X-ray fluorescence machine reads the exact composition in seconds without damaging the piece. Most established jewellers have one, and reputable ones will show you the reading on the screen.
This is the only practical way to grade old family gold — and it is what happens anyway when you exchange it, so it is worth knowing the number before you negotiate.
Bring your old gold in
We test old gold openly and show you the purity reading before discussing any exchange value. There is no charge for finding out what you own.
Cleaning gold jewellery safely
Most dullness is not tarnish — gold does not tarnish. It is a film of soap, body oil, sweat, talc and cosmetics. It comes off easily with the gentlest possible method.
The method for plain gold
- Fill a small bowl with warm — not hot — water and a few drops of mild dish soap.
- Soak for 15–20 minutes. This does most of the work; let it.
- Brush very gently with a soft toothbrush, paying attention to chain links and the backs of settings where grime collects.
- Rinse in clean water. Close the drain first — this is how earrings are lost.
- Pat dry with a soft lint-free cloth and let it air-dry fully before storing.
Done every couple of months, this keeps everyday pieces looking exactly as they should. For plain gold you genuinely do not need anything stronger.
What never to use
| Avoid | Why |
|---|---|
| Toothpaste | Mildly abrasive — it dulls the polish and leaves fine scratches over time. A stubbornly persistent piece of internet advice. |
| Baking soda | Abrasive, and reacts badly with some stones and settings. |
| Bleach or chlorine | Attacks the alloy metals and can permanently discolour gold. Remove jewellery before swimming pools. |
| Ammonia-based cleaners | Too aggressive for stone-set and antique work. |
| Ultrasonic cleaners | Vibration loosens stone settings and can crack softer stones. Fine in professional hands on the right pieces; risky at home. |
| Hot water on kemp pieces | Softens the lac adhesive holding traditional stones. |
Antique, kemp and stone-set pieces
These need a different approach, and the honest advice is mostly leave them alone.
- Antique finishes are deliberately oxidised. That soft darkened look is the design. Cleaning it enthusiastically strips the finish and it cannot be put back at home.
- Kemp stones are often set with lac, a natural resin that softens in warm water. Soaking a temple jewellery piece can loosen stones.
- Pearls and emeralds are porous and soap dulls them permanently.
- Enamel and meenakari work chips under brushing.
For all of these: wipe gently with a dry, soft cloth after wearing, and bring them in when they genuinely need attention.
Storing gold properly
- Separately. Gold scratches gold. Soft pouches or a partitioned box.
- Dry. Humidity accelerates tarnish on the alloy metals, and Tamil Nadu is not a dry climate. A silica sachet in the box helps.
- Away from cosmetics. Perfume, hairspray and lotion are the main culprits behind dullness. Jewellery goes on last, comes off first.
- Chains loosely fastened so they do not knot.
- Photograph everything and keep the invoices with the hallmark details — useful for insurance, essential for a future exchange.
When to bring it to a jeweller
- A stone feels loose or rattles — stop wearing it immediately.
- A clasp is stiff, weak or has been repaired with a temporary link.
- A chain has stretched or a link looks thin.
- The piece is antique, enamelled or heavily stone-set and needs cleaning.
- You want a proper polish — professional polishing removes a microscopic amount of gold, so it is not something to do every year, but it restores a piece beautifully when it is genuinely needed.
- You are unsure what you have inherited and want it tested.
Bring it in
We clean, check and re-tip settings for pieces bought from us, and we are happy to look at anything else. If a repair is not worth doing, we will say so rather than take the work.
Questions we are asked
My gold has turned slightly dark. Is it fake?
Almost certainly not. 22K gold contains copper and silver, and those alloy metals react to sweat, humidity and cosmetics. A gentle wash usually restores it completely.
Can I wear gold in the shower?
Better not to. Soap builds a film, and hard water leaves deposits. Chlorinated water is genuinely harmful to the alloy.
Does cleaning reduce the weight?
Washing, no. Professional polishing removes a very small amount of metal, which is why it should be occasional rather than routine.
How often should I clean?
Everyday pieces every couple of months. Ceremonial pieces after each wearing — a dry wipe is usually enough.
Is unmarked old gold worth less?
Not necessarily. Plenty of unhallmarked family gold is perfectly good 22K. It simply has to be tested before exchange, and the tested purity is what determines its value.