How to Tell if Gold Is Real: The 18K 750 Hallmark Explained

Gold is one of the few things people buy expecting it to keep its value, so it is worth knowing exactly what you are paying for. The good news is that genuine gold jewellery carries clear signs of what it is made of. Here is how to read them, and how to check a piece without damaging it.

Karats in plain numbers

Gold purity is measured in karats out of 24. Pure gold is 24 karats, but it is very soft, so jewellery is usually made from an alloy: gold mixed with small amounts of silver, copper or other metals for strength and colour. The number stamped on the piece tells you how many parts per thousand are pure gold.

• 18K = 750: 75% pure gold.
• 21K = 875: 87.5% pure gold.
• 22K = 916: about 91.6% pure gold.
• 24K = 999: 99.9% pure gold, mostly used for bars and coins.

So a ring stamped 750 and a ring stamped 18K are saying the same thing. Many pieces carry the number only, without the letter K.

Where to find the hallmark

Look inside a ring band, on the clasp or the small tag next to it on chains and bracelets, and on the post or back of earrings. Marks are often tiny, so use your phone camera's zoom or a jeweller's loupe. Besides the purity number you may see a maker's or assay mark: in the UAE, gold jewellery is commonly tested and hallmarked by approved laboratories before it is sold.

Safe checks you can do yourself

1. Read the stamp

A clear, evenly struck purity mark is the first thing to look for. On its own it is not final proof, because stamps can be copied, but genuine gold from a reputable seller will always have one.

2. Try a magnet

Gold is not magnetic. If the main body of a piece is pulled towards a strong magnet, it is not solid gold. Passing the test is a good sign rather than proof, and small parts such as clasp springs may contain steel, so test the piece itself.

3. Check the edges

Look closely at places that rub the most: clasps, the inside of rings, the edges of pendants. A different colour showing through, such as a grey or coppery tone, usually means a thin gold layer over another metal.

4. Ask for the paperwork

A trustworthy seller states the karat and the weight in grams, gives you an invoice that shows both, and provides a certificate of authenticity. Keep them together; you will need them if you ever resell, insure or exchange the piece.

What not to do at home

• Do not bite it. It proves nothing and can leave marks, especially on high-karat pieces.
• Do not scratch it on a tile, stone or file. You will damage the surface and still not know the karat.
• Do not use acid kits. Testing acids are corrosive, give unreliable results in untrained hands and can stain or pit the metal.
• Do not hold it over a flame. Heat can damage stones, solder joints and any finish.

If you want certainty, take the piece to a reputable jeweller or testing laboratory. Many use X-ray fluorescence (XRF) machines, which measure the gold content in seconds without harming the jewellery.

Words that mean "not solid gold"

• GP, GEP, HGE, RGP: gold-plated or electroplated: a very thin gold layer over base metal.
• GF or "gold filled": a thicker gold layer bonded to a base metal core.
• Vermeil: gold plating over silver.
• "Gold tone" or "gold colour": describes the colour only, not the metal.

How we do it at Dubai Gold Jewellery

Every piece we sell is hallmarked 18K gold (750) and arrives with a certificate of authenticity, and every product page shows the weight in grams. You also have 14 days to return a piece and a 6-month warranty on manufacturing defects. Read more on our Warranty page, or browse gold bracelets and the full 18K gold collection.