Identifying Real Gold: What 585, 750, and Co. Mean – and How to Protect Yourself from Fakes

"Is this real gold?" is a question many people ask – and too rarely answer before they buy. The result: millions of euros are spent annually on gold-plated fashion jewelry marketed as gold without truly being so. Not always due to fraud, often simply due to unclear communication and a lack of knowledge on the buyer's part.

This article will show you how to reliably identify real gold – whether in a store, online, or when buying used jewelry.

The Fineness Mark: The Only Reliable Feature

In Germany and throughout the EU, precious metals sold as such must be marked with a fineness stamp. This stamp is engraved directly into the metal of the piece of jewelry – not printed on the packaging, not noted on an accompanying certificate, but physically on the piece itself.

The most important gold stamps and their meaning:

585 – 14-karat gold, 58.5 percent fine gold content. Standard for wedding rings, everyday jewelry, the main part of the gold jewelry market in Germany. Robust, suitable for everyday wear, good value for money.

750 – 18-karat gold, 75 percent fine gold content. Richer color, softer, higher material value. Often used for jewelry with valuable gemstones.

333 – 8-karat gold, 33.3 percent fine gold content. The cheapest real gold. Approved for jewelry in Germany, but not recognized as a precious metal in some other EU countries.

999 or 999.9 – Fine gold, 99.9 percent pure. Practically unsuitable for jewelry (too soft), mainly for bars and coins.

What is not a real gold stamp: "18K GP" (Gold Plated), "GF" (Gold Filled), "HGE" (Heavy Gold Electroplate), "Gold Tone", "Vermeil" – all terms for gold plating on non-precious metal bases.

Where to Find the Stamp

For necklaces: on the clasp or on the connecting link next to the clasp. For rings: on the inside of the band, usually next to any manufacturer's or hallmark. For earrings: on the post or hook, depending on the construction. For pendants: on the bale end or on the back.

The stamp is often very small and requires a magnifying glass or the macro lens of a smartphone to read. This is normal – reputable manufacturers stamp, even if it's difficult.

If a dealer claims the stamp is "too small for this piece" or "fell off" – these are not valid excuses. In Germany, the rule is: no stamp, no regulated proof. If you don't want to take the risk, buy elsewhere.

The Weight Test: What Gold Reveals

Real gold is heavy – significantly heavier than most other metals. The density of 585 gold is about 13 to 14 g/cm³ (depending on the alloy composition), while brass is 8.5 g/cm³ and aluminum is 2.7 g/cm³.

In everyday terms, this means: A real gold chain feels noticeably heavier in the hand than a visually similar chain made of brass or silver-plated copper. The sense of weight is not precisely measurable without a scale, but it is clearly perceptible with some experience.

Additionally: If a seller specifies the weight in grams and you can calculate the material value yourself – weight × fineness × current fine gold price – this provides a plausibility check for the price. Selling a chain with a material value of 200 euros according to the gold price for 35 euros doesn't add up mathematically.

What Gold-Plated Jewelry Is – And What It Isn't

Gold-plated jewelry is not a scam if it is communicated as such. The problem arises when communication is imprecise or when buyers don't know the difference.

Gold Plated: A thin layer of gold (0.5 to 5 micrometers) is electroplated onto a base metal. Inexpensive to produce, initially looks high-quality, but wears off within months to a few years depending on the layer thickness and use.

Gold Filled: A thicker layer of gold, mechanically bonded to the base metal. More durable than standard gold plating, but still not solid gold. Common in the USA, less common in Europe.

Vermeil: Gold-plated 925 silver with a minimum layer thickness of 2.5 micrometers. A higher quality gold plating variant, but the base metal is silver, not gold.

The crucial difference to solid gold: In all gold plating variants, the supporting metal is not a precious metal. The gold content is negligible. The material value is a fraction of real gold.

How to Check Used Jewelry

The same principles apply to used jewelry, but additional checks are useful. First: look for a stamp, as described above. Then: read the stamp. A genuine 585 stamp is very precisely embossed, evenly distributed, without blurred edges.

If you are unsure: Any jeweler can test precious metal with a touchstone and acid (gold assay) within minutes. This takes no longer than five minutes and is free in many workshops or costs a small fee. X-ray fluorescence (XRF) devices, available in some jewelers' workshops, also determine the fineness non-destructively and very precisely.

What This Means Online

When buying gold jewelry online, a simple rule applies: a reputable dealer explicitly states the fineness mark in the product text and indicates the weight in grams. Anyone who does not do this either does not have solid gold to sell or does not value transparency. Both are warning signs.

In addition: a complete imprint with a real address, at least 14 days right of withdrawal (legally required), genuine customer reviews with photos, and secure payment options with buyer protection.

At Corelune, the fineness mark is specified for every piece, the weight in grams for all necklaces and bracelets, and the complete imprint is always accessible. This is not an extra – this is standard for any dealer who values transparency.

→ Further articles: 585 or 750 Gold: What's the Difference? | Skin-Friendly Jewelry: What Really Helps

Frequently Asked Questions About Identifying Real Gold

What does "750 Gold" on a ring mean?

750 means 750 parts fine gold per 1000 – i.e., 75 percent pure gold. This corresponds to 18 karat. It is the highest fineness used in jewelry after 999 fine gold. The rest of the alloy consists of copper, silver, or other metals that influence hardness and color.

Is "18K Gold Plated" real gold?

No. "18K Gold Plated" means that the base metal (usually brass or copper) has been coated with a thin layer of 18-karat gold. The designation "18K" describes the quality of the coating, not the base metal. It is not solid gold.

Can I test real gold with a magnet?

Only as a first rough test. Real gold is not magnetic. If a piece sticks to a magnet, it is not gold. If it doesn't stick, it could be gold – but the test does not exclude other non-magnetic metals (brass, copper, aluminum). The stamp test is more reliable.

Where can I have old gold jewelry tested?

At any jeweler with their own workshop. A visual inspection is usually free. A chemical test (touchstone + acid) or XRF analysis costs nothing or a few euros, depending on the business. For valuable pieces, an appraisal by a publicly appointed expert is also worthwhile.