Precious metal quality marks

Canada's Precious Metals Marking Regulations list the marks allowed for each metal and the minimum purity behind each one. The table sums them up.

Gold is marked in karats (written K, Kt., Ct., C, “karat” or “carat”) or in decimals. The karat number is out of 24, so 14K is 14/24, about 58.3% gold, and 10K is about 41.7%. 14K is 583 or 585 parts per thousand, which is why many 14K pieces are stamped 585; UK hallmarking also lists 585 as a standard gold mark. The lowest gold quality that may carry a quality mark in Canada is 9 karats.

Silver, platinum and palladium are marked by name or abbreviation. Each has its own entry: sterling silver, platinum and palladium.

The Act says that when a quality mark is applied, a registered trademark, or one with an acceptable application on file, must be applied too. Where the quality mark is stamped, branded, engraved or imprinted, the trademark must go on the same way. That is why a ring often carries two marks side by side: 14K and a small logo or set of initials. A registered trademark belongs to someone, so it gives you a name to ask about.

There is an exception. An article hallmarked under UK law, or carrying a mark applied by a foreign government that truly shows its quality, does not need the Canadian trademark. Imported jewellery can therefore be marked quite differently.

No, and the difference is worth knowing. A UK hallmark is a set of marks applied after an assay office has independently tested the piece. The compulsory marks are the sponsor's mark, a fineness mark in parts per thousand and the assay office's mark.

In Canada the dealer, meaning the manufacturer, importer or seller, applies the quality mark, and checking comes afterwards. Inspectors can enter a dealer's premises and seize articles they believe are marked contrary to the Act, and a dealer who breaks the rules can be fined up to $500 on summary conviction. The Act sets the standard the metal must meet; it does not describe an assay office that tests each piece before it is stamped.

Canada also has an optional national mark, a maple leaf inside the letter C. It is reserved for articles wholly manufactured in Canada and applied by dealers the Commissioner of Competition has authorized.

A stamp is narrower than it looks.

• Not the finish. Plated pieces have their own marks, such as “gold plated” or “vermeil”, and the Act bars marks that promise plating will last for a set time.
• Not every part. The regulations list parts that are exempt from assay, including earring setting posts and the tubes and posts used to attach drilled stones. The stamp does not vouch for them.
• Not exact purity. The table's tolerances mean a stamped piece can test slightly under its figure.
• Nothing about stones. The mark covers metal only. For diamonds, see the diamond grading report.

Look for two things: a quality mark such as 10K, 14K, 18K, 925, sterling, Plat. or Pall., and a trademark applied the same way. Check that the metal matches what you were told, and ask who owns the trademark. The entries for 10K, 14K and 18K gold explain what each grade means.

Older, imported and secondhand pieces may carry different marks or worn ones. The Act makes it an offence for a dealer to destroy, deface or make illegible a mark applied under it, so ask that marks stay legible after a repair or resizing.

A stamp is a claim by the seller, not a certificate. If you want independent confirmation, a jewellery appraisal is the usual route. Metal is a choice to settle early on a custom engagement ring, and you can compare options in the design studio or at a showroom.