Metals in Gold Jewellery: What's Inside and Why It Affects What You Get Paid
A factual guide to what's inside your jewellery and what it means when you sell.
Alok Parmar
June 09, 2026
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Why pure gold can't be worn
The metals in gold jewellery are not impurities — they're structural. Pure gold (24K) is softer than a human fingernail. A ring made from it would dent within days. Alloying with copper, silver, zinc, or other metals raises durability 3–5x. Every karat below 24 is a gold-metal mixture, and the mix determines colour, hardness, and what a buyer can actually recover when you sell.
Coins and bars exist in pure gold because they sit in a locker, not on your wrist. The moment jewellery needs to survive daily wear, the gold has to be mixed.
FUN FACT
The 24-part gold purity system traces back to ancient Roman times, where the Roman gold coin was divided into 24 units called siliquae for measuring purity.
The term Karat later evolved from the Greek word keration (carob seed), used as a weight measure.
The karat system
Karat measures gold as a fraction of 24 parts. The BIS hallmark fineness (e.g. 916, 750) confirms purity — but says nothing about what the remaining metals are.
| Karat | Gold % | Mark | Common use |
|---|---|---|---|
| 24K | 99.9% | 999 | Coins, bars |
| 22K | 91.67% | 916 | Traditional jewellery |
| 18K | 75% | 750 | Diamond jewellery |
| 14K | 58.5% | 585 | Fashion pieces |
The metals inside gold jewellery and what each one does
The non-gold portion determines colour, hardness, and resale reality.
Cu
Copper
Warmer, redder tone · High hardness · Negligible resale value | Most Common
Backbone of Indian 22K. Hardens gold and adds warmth. Can leave a green mark on skin — a harmless chemical reaction, not an allergy.
Ag
Silver
Lighter yellow tone · Some independent value
Lightens colour and improves ductility. Counteracts copper's reddening. Present in small amounts in most yellow gold.
Zn
Zinc
Minor brightening · Negligible resale value
Added in small amounts for hardness and better casting. Became the standard safe solder component after cadmium was restricted.
Ni
Nickel
White/silver colour · Allergen risk · Negligible resale value | White gold only
Creates the white colour in cheaper white gold. A contact allergen — rhodium coating provides an initial barrier but wears off with daily use.
Pd
Palladium
White colour · Hypoallergenic · Real precious metal value | Premium
Used in high-end white gold instead of nickel. Hypoallergenic and genuinely valuable as a precious metal — flag it explicitly when selling, as it is rarely captured in standard resale.
Yellow, white & rose gold
Not different products — the same gold alloyed with different metals to produce different colours.
Yellow
Gold + copper + silver
Rose
Higher copper, less silver
White
Nickel or palladium + rhodium coat
At resale, colour is irrelevant. A 22K rose, yellow, and white piece all have the same gold content — and the same valuation.
Hidden materials that reduce your payout
Many pieces contain non-gold materials beyond the alloy — all deducted at resale.
1
Lac filling
Hollow bangles are often filled with lac resin for strength. A 20g bangle may hold only 12–14g of gold. Bring your original purchase receipt showing net gold weight if you have it.
2
Hollow construction
Large bangles, chains, and earrings are often hollow shells. You are paid for actual gold weight — not visual size. If a large piece feels unexpectedly light, it is hollow.
3
Meenakari (enamel)
Enamel is coloured glass fused onto the surface. It adds measurable weight that must be deducted. Artisan value of the craft is not reflected in a standard gold transaction.
4
Gemstones
Stones are deducted from gold weight and typically not valued separately. For certified diamonds, get a gemmologist assessment before selling.
5
Solder joints
Every join is soldered with a lower-karat alloy. Heavily constructed pieces have multiple solder points that reduce the average gold content below the stamped karat.
6
Rhodium coating
The bright white finish on white gold is an electroplated rhodium layer. Zero recoverable value at resale — white gold is valued only on the underlying gold alloy.
KDM gold & cadmium
KDM refers to cadmium-based solder once widely used in Indian gold manufacturing. Cadmium is a toxic heavy metal — it accumulates in the body and posed serious health risks to jewellers who worked with it. It has since been banned from hallmarked gold, and safer zinc-based soldering is now standard.
If you have old, unhallmarked jewellery, it may contain KDM solder. Flag this when selling — buyers may account for the additional processing involved.
Now you know what's inside your jewellery. Here's what it's actually worth.
The metals, fillings, stones, and solder described above all factor into the final calculation. Our expert comes to your home, tests the gold in front of you using a touchstone and acid, explains every deduction, and shows you the math at the live domestic gold rate. You decide whether to sell.
Frequently Asked Questions
My gold jewellery is stamped 22K but the buyer said the actual purity tested lower. Is that normal?
It's more common than people expect. The 22K stamp reflects the gold content of the main alloy, but every piece also has solder joints at clasps, links, and repairs — and solder is a lower-karat alloy. Hollow pieces may also contain lac or wax filling that adds to the gross weight without adding gold. When a buyer tests the recoverable purity after accounting for all of this, the result can sit slightly below the stamped karat. A gap of 1–2% is typical; anything larger is worth questioning.
Does the colour of my gold jewellery — yellow, white, or rose — affect how much I get when I sell?
No. Colour is determined by which metals were mixed into the alloy — more copper gives rose gold, nickel or palladium gives white gold — but the gold content is the same across all three at the same karat. A 22K rose gold bangle and a 22K yellow gold bangle pay out identically. The only thing that changes your payout is net gold weight, tested purity, and the live domestic rate on the day.
I have a hollow bangle. Will I get significantly less for it than a solid one of the same weight?
Not necessarily less per gram of actual gold — but the gross weight will be misleading. A hollow bangle that weighs 20g on the scale may only contain 12–14g of recoverable gold once the lac filling is deducted. You're paid on the net gold weight, not the total weight. If you have the original purchase receipt showing the net gold weight, bring it — it gives you a reference point before testing begins.
My jewellery has small diamonds in it. Do they add anything to the resale value?
In a standard gold transaction, stones are deducted from the gross weight and not valued separately. The gold around them is what gets paid out. Certified diamonds are the exception — if you have a gemmologist's certificate for a significant stone, get a separate assessment before selling, because a gold buyer's transaction is not the right place to realise diamond value.
I have old jewellery that might have KDM solder. Does that affect my payout?
It can, but not because KDM gold is worth less per se. Cadmium-based solder may require additional processing at the refinery, and some buyers factor that into their offer. The more important thing is to flag it upfront rather than have it discovered mid-valuation. If your piece is old, unhallmarked, and was bought before 2000, mention it when scheduling — a buyer who values gold fairly will account for it transparently rather than using it as a surprise deduction.