Hallmarks tell you a lot, home tests very little. Here is what is worth checking.
The most reliable sign that jewellery is gold is its legal hallmarks. Home tests can show that a piece is not gold, but they cannot confirm its karat. For a reliable answer you need professional testing.
1. Check the marks
Look at the piece with a magnifier, especially inside a ring, on the clasp or on an earring post. In Romania, gold jewellery offered for sale must carry three marks:
the fineness mark: a number, such as 585 for 14K or 750 for 18K;
the responsibility mark: the sign of the company that placed the piece on the market, registered with ANPC, the Romanian consumer protection authority;
the state mark: applied only by ANPC. An equivalent mark from an EU or EEA country or from Turkey is also accepted.
The legal fineness grades for gold in Romania are 333, 375, 500, 585, 750, 833, 900, 916, 986 and 999. Any other number is not a legal grade. More on karats is in Gold karats and purity hallmarks.
2. Watch for plating marks
Some marks show that a piece only has a thin layer of gold on the surface. The most common are GP, GF, HGE, RGP and “plaqué”. For example, “18K GP” means plated with 18K gold, not solid gold. Another sign is a different colour on edges and worn areas.
3. Home tests and their limits
Magnet. Gold is not attracted to a magnet. If the piece is strongly attracted, it is not gold. Limit: many cheap metals are not magnetic either, and clasps sometimes contain a steel spring.
Density. Gold is heavy: 19.3 g/cm³ for 24K and about 13–14.5 g/cm³ for 14K. Brass is around 8.5 g/cm³. Limit: you need a scale accurate to 0.01 g, the error is large with small pieces, and some fakes use metals just as heavy.
Appearance. Wear that shows a different metal underneath points to plating. Limit: it says nothing about karat.
Avoid tests that can damage the piece: scratching on ceramic, a flame, vinegar or biting. They are unreliable and can leave marks.
4. Professional testing
Touchstone and acid: quick and cheap, gives an approximate result.
XRF analyser: measures composition without damaging the piece. Thick plating can still give a false reading.
Fire assay (cupellation): the most accurate method, but it uses up a small amount of metal.
For an official assessment, you can request an expertise report from ANPC’s Directorate for Precious Metals and Precious Stones.
5. When you buy gold
Always ask for a fiscal receipt or invoice. A warranty certificate on its own is not a fiscal document. The seller must display their authorisation and explain the marks on the pieces.
Want a piece checked, or want to sell scrap gold? At our showroom in Pitești we also test pieces you do not want to sell, for a fee. Contact us for details.
Source: InfoCons – Buyer’s guide to precious metal goods (in Romanian).