Start with purity, not the shop bill
A 24K coin and a 22K jewellery item do not contain the same proportion of gold. BIS permits bullion/coin certification in 999 or 995 fineness under its refinery/mint framework, while 22K jewellery is commonly identified as 916 fineness. That means a conversion should be understood in terms of fine-gold content first, before making charges, tax and retailer terms are added.
The theoretical purity conversion
For illustration, a 10 gram 999 coin contains about 9.99 grams of fine gold. If all of that fine gold were used in a 916 alloy, the theoretical alloy weight would be roughly 9.99 ÷ 0.916 = 10.91 grams because other metals are added to create the 22K alloy.
That calculation is a purity relationship, not a promise of what a jeweller will hand over. Actual exchange transactions can involve testing, commercial valuation, product selection, making charges, stones, wastage policies and retailer-specific terms.
| Step | What is being measured |
|---|---|
| Coin weight | Total weight of the 24K/999 or 995 product |
| Fine-gold content | Coin weight × fineness |
| 22K equivalent | Fine-gold content ÷ 0.916 |
| New jewellery bill | Metal value + making/design + stones if any + applicable GST |
What can reduce the value credited to the transaction?
The phrase “deduction” can refer to several different things. Ask the retailer to name each one separately rather than giving only a final exchange figure.
- Purity/test adjustment: the coin may be tested to confirm fineness.
- Buyback or exchange policy: the retailer may have different terms for its own product and another brand's product.
- Commercial premium: the premium originally paid for packaging or branding is not the same as fine-gold content.
- New jewellery making charge: converting metal into a new ornament creates a new workmanship cost.
- Stones or non-gold components: these are separate from the gold value.
- GST on the new retail transaction: CBIC states that retail jewellery is taxed at 3% of the total transaction value whether making charge is separately shown or not.
Exchange is not the same as melting at home
In practice, most buyers should think of the transaction as a valuation and new purchase rather than as a literal one-for-one physical remelting of their exact coin into the chosen ornament. The retailer may credit the old gold value and issue a new invoice for the new item.
This distinction is useful because it lets you compare the transaction in rupees. Ask: “How much value are you crediting for my coin?” and “What is the complete invoice for the new 22K item?” The difference between those two figures is easier to audit than a vague percentage deduction.
Checklist before exchanging a 24K coin
- Confirm the coin's fineness and weight.
- Keep the original invoice and packaging if available.
- Ask whether cross-brand coins are accepted.
- Ask whether the retailer uses cash-buyback or exchange valuation.
- Get the credited rupee amount before choosing the new jewellery.
- Confirm the new item's 22K/916 hallmark and HUID.
- Ask for net gold weight, making charge, stone value and GST on the new invoice.
FAQ
Does 10g of 24K become exactly 10g of 22K jewellery?
No. 22K contains added alloy metal, so the purity relationship is different. The actual retail transaction also depends on design, charges and the jeweller's exchange policy.
Is 24K the same as 999 gold?
In retail language, 999 fine gold is commonly described as 24K. BIS's bullion/coin framework covers 999 and 995 fineness.
Can a jeweller charge making charges again after I exchange a coin?
They may. The exchange credit for the old gold and the making/design charges for the new jewellery are separate parts of the transaction, and the exact treatment depends on the retailer's exchange policy. Ask for both amounts separately before completing the purchase.
