By The Eye desk · Last verified 4 October 2026
The numbers stamped on jewellery show the fineness of the precious metal in parts per thousand. For gold, 999 is pure (24K), 916 is 91.6% (22K), 750 is 75% (18K), 585 is 58.5% (14K) and 375 is 37.5% (9K). For silver, 925 is sterling. For platinum, 950 is the common jewellery standard. A purity number alone is only the maker’s claim. A full hallmark adds independent testing, and in Singapore that comes from the Singapore Assay Office (SAO), whose hallmark has three parts: the jeweller’s mark, the SAO lion head and the purity mark. Note that hallmarking is voluntary in Singapore, unlike in the United Kingdom, where it is compulsory.
A tiny stamp tells a big story once you know the code. Here is how to read it.
Quick facts
- Fineness numbers are parts per thousand: 916 means 916 parts gold in 1,000.
- Gold standards used in UK hallmarking: 999, 990, 916.6, 750, 585 and 375.
- Silver standards: 999, 958, 925 (sterling) and 800.
- Platinum standards: 999, 950, 900 and 850.
- In Singapore, hallmarking is voluntary; the Singapore Assay Office is the accredited hallmarking laboratory.
- An SAO hallmark has three marks: the jeweller’s mark, the lion head and the purity mark.
What do the numbers mean?
| Stamp | Metal | Purity | Karat (gold) | Where you see it |
|---|---|---|---|---|
| 999 | Gold | 99.9% | 24K | Bars, coins, some traditional pieces |
| 916 | Gold | 91.6% | 22K | Traditional Chinese, Indian and Malay gold jewellery |
| 750 | Gold | 75% | 18K | Fine jewellery and diamond settings |
| 585 | Gold | 58.5% | 14K | Everyday and imported jewellery |
| 375 | Gold | 37.5% | 9K | Lower-priced gold jewellery |
| 925 | Silver | 92.5% | n/a | Sterling silver jewellery and cutlery |
| 999 | Silver | 99.9% | n/a | Fine silver, bullion |
| 950 | Platinum | 95% | n/a | Platinum rings and settings, often stamped Pt950 |
Worked example: a 10g chain stamped 916 contains about 10 × 0.916 = 9.16g of gold. The same weight in 750 contains 10 × 0.75 = 7.5g. That difference is why 22K and 18K pieces of the same weight are priced differently. Our guide to 916 gold, workmanship charges and buyback explains how that plays out at the counter.
How do you read a full hallmark?
- Find the purity mark. A number such as 916 or 750, sometimes with a karat mark like 22K alongside.
- Find the jeweller’s or maker’s mark. Initials or a symbol identifying who made or sponsored the piece.
- Look for the assay office mark. In Singapore, the SAO’s lion head shows the piece was independently tested; in the UK, each assay office has its own symbol.
- Check the receipt matches. The invoice should state the metal, purity and weight.
- Use a loupe. Stamps are tiny; a jeweller’s magnifier helps, and any reputable shop will show you.
Which marks should make you pause?
- GP, GEP or HGE usually indicate gold plating over another metal, not solid gold.
- GF usually indicates gold-filled: a thicker layer of gold bonded to a base metal.
- Vermeil generally means gold over sterling silver.
- A karat mark with no maker’s mark or receipt is only a claim; anyone can stamp a number.
- Prices well below the gold rate for the weight suggest the piece is not what the stamp says.
The WahLiao Verdict
Read the number, then look for proof behind it. For gold in Singapore, the best assurance is the full Singapore Assay Office hallmark with the lion head, plus a receipt stating purity and weight from a jeweller you trust. For silver, look for 925; for platinum, 950 or Pt950. Treat plated marks as costume jewellery, priced accordingly, and walk away from any bargain that beats the metal price. For stones, our diamond 4Cs guide takes it from there.
Questions people ask
Is hallmarking compulsory in Singapore?
No. The Singapore Bullion Market Association notes that hallmarking is voluntary in Singapore, unlike in the United Kingdom or Thailand, where it is mandatory.
What does 916 mean on gold?
916 parts of gold per 1,000, or 91.6% gold, which is 22K. The rest is other metals that make the piece harder and more durable.
What does S925 mean?
It is a common way of marking sterling silver, 92.5% pure. The S stands for silver.
Can I get my jewellery tested?
Many jewellers and gold dealers can test purity, and the Singapore Assay Office is Singapore’s accredited hallmarking laboratory. Contact the provider to ask what services it offers individuals, what method it uses and whether the test is non-destructive.
Sources: Singapore Bullion Market Association, the importance of hallmarking gold; Assay Office London, hallmarking guidance and fineness standards. The Eye explains; it does not endorse.
Read next: 916 Gold Explained: Purity, Workmanship Charges and How Buyback Works · Diamonds Explained: The 4Cs and What a Grading Report Tells You · Back to The Eye
For what’s worth it this week, with the bill shown, read The WahLiao Week.
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