Key takeaways
- Purity stamps: 999 = 24K, 916 = 22K, 750 = 18K, 585 or 583 = 14K, 417 = 10K.
- India: a BIS hallmark has three parts: BIS logo, purity (e.g. 22K916) and a 6-character HUID. Check it in the BIS CARE app.
- Canada: quality marks are optional, but if a piece is marked, it must also carry a trademark.
- A magnet test can only show something is not gold. Acid tests scratch the piece.
- XRF testing is non-destructive. Fire assay, the method the BIS uses for purity tests, is the most exact but destroys a small sample.
What do the numbers stamped on gold mean?
Most gold jewellery shows purity in karats (K) or in parts per thousand:
| Stamp | Karat | Gold content |
|---|---|---|
| 999 or 9999 | 24K | 99.9% or 99.99% |
| 995 | 24K (bars) | 99.5% |
| 916 | 22K | 91.6% |
| 875 | 21K | 87.5% |
| 750 | 18K | 75% |
| 585 or 583 | 14K | 58.5% / 58.3% |
| 417 | 10K | 41.7% |
| 375 | 9K | 37.5% |
Marks that mean plated, not solid: under Canada’s rules, “G.F.” (gold filled), “R.G.P.” (rolled gold plate) and “G.E.P.” or “gold plated” (gold electroplate) describe a thin layer of gold over another metal.
How do you read and check an Indian BIS hallmark?
In India, hallmarking is run by the Bureau of Indian Standards (BIS). Since July 1, 2021, the BIS says a hallmark has three marks:
- The BIS logo (a triangle mark).
- The purity in karat and fineness, such as 22K916.
- A HUID (Hallmark Unique Identification), a six-character code of letters and numbers unique to each piece.
The BIS lists these gold grades: 14K (585), 18K (750), 20K (833), 22K (916), 23K (958) and 24K (995).
To check it: install the BIS CARE app and use “Verify HUID”. Enter the six characters. The result should match your piece’s type and purity. If it does not match, ask the jeweller.
Older pieces from before 2021 may carry an older hallmark without a HUID. In India, a BIS-recognised Assaying and Hallmarking Centre will test a hallmarked piece by fire assay for a fee of Rs. 200, per the BIS FAQ.
What do Canadian gold marks mean?
Canada’s rules are in the Precious Metals Marking Act, explained by the Competition Bureau:
- Marking is optional. A seller does not have to stamp gold, but any mark must be true.
- Gold marks start at 9K. Karat marks (K, Kt) or decimal marks may be used for gold of 9 karat or higher. 10K, 14K and 18K may be shown as .417, .583 and .750, or without the decimal point.
- A trademark must go with it. If a piece has a quality mark, it must also carry a trademark that has been registered or applied for in Canada. UK hallmarks and certain foreign government marks are exceptions.
- Small tolerance. Gold from 9K to 24K may be up to 3 parts per thousand below the mark, or 7 parts per thousand if the piece contains solder.
So a Canadian 14K ring may say “14K” or “583” with a maker’s mark beside it. A purity stamp with no trademark is a warning sign.
Can you test gold at home?
Home tests can catch obvious fakes. None of them can prove gold is real or tell you its karat.
- Look closely. Use a magnifier to find the stamp and trademark. Check worn edges and clasps for a different metal showing through, a sign of plating.
- Magnet test. Gold is not magnetic. If a piece sticks strongly to a magnet, it is not solid gold, or it has a steel part such as a spring in the clasp. Passing the test proves little, since many other metals are not magnetic either.
- Weight and size. Gold is very heavy for its size. A piece that feels light may be hollow or not gold, but this needs scales and care to judge.
- Avoid acid kits on good pieces. An acid test needs a scratch on the piece, which removes a little metal and can lower its value.
For bullion, check the maker’s security features. Royal Canadian Mint Gold Maple Leaf coins have precision radial lines, a micro-engraved maple leaf with the year visible under magnification, and, on coins dated 2014 and later, Bullion DNA anti-counterfeiting technology.
How do professionals test gold?
- XRF (X-ray fluorescence): a machine reads the metals in the piece in seconds without marking it. Some dealers and jewellers have one; ask for the printout.
- Acid or touchstone test: cheap and quick, but it needs a scratch or rub and only gives a range.
- Fire assay: a lab melts a small sample to measure the gold exactly. It is the method the BIS uses for its paid purity tests. It destroys the sample, so it is used for bars and disputes, not everyday jewellery.
If you plan to sell, a free XRF test at a dealer is often the easiest check. Read how to sell gold in Canada next.
Once you know the karat, find its value with the gold value calculator and compare with today’s gold price by karat.