Stamps and hallmarks on precious metals

Additional information > The fundamentals of precious metals – a broad introduction to the basic principles > Deciphering hallmarks & stamps on precious metal products

Common markings on watches, jewellery and bullion goods

Authentic jewellery, luxury watches and bullion coins and bars are considered material assets for securing private assets. Precious metals, especially gold, silver, platinum and palladium, have enjoyed an enduring reputation for value stability. They can protect against inflation, serve as an inheritance, or support retirement plans. Precious metals display different hallmarks and stamps, and these markings provide information about the value of a piece, and supply proof of the origin and quality of the material used.

The authenticity of any type of precious metal is of crucial importance in any sale or purchasing context, and even experienced buyers and collectors may sometimes find it difficult to distinguish between real and fake items. Elaborate counterfeits can be made to look deceptively real these days, and may even pass some initial testing. This applies not only to items such as gold coins or silver bars, but also to luxury goods such as jewellery or expensive watches. To help prevent investors purchasing essentially worthless imitations, this article explains some key points to consider, which are summarised below.

The characteristic markings on precious metal coins

Gold and white-metal coins traded as investments or collectors’ items have embossed markings on the coin surface in addition to their individual coin motifs. This helps to make each coin clearly identifiable. The fineness of the metal material, commonly expressed in three or four digits as parts per 1,000, is a key consideration. Many popular gold coins such as the Australian Kangaroo, Maple Leaf or Vienna Philharmonic, are now produced to a fineness of 999.9/1000, which corresponds to pure gold. Many silver coins also have this same fineness rating, while most platinum and palladium coins have a material quality of 999.5/1000.

In addition, precious metal coins are usually marked with their weight unit, in ounces or grams, and with a nominal face value expressed in the national currency of the issuing country. Coins can also include other information such as a product or series name, the initials of the motif designer for each side coin face, and a mintmark indicating where each coin was minted. Precious metal coins issued in limited editions often come with a consecutively numbered certificate of authenticity included in the packaging. For bullion coins available in larger packaging units, the respective coin tubes or master boxes are sealed using a seal bearing specific information relevant to the bullion contents.

Hallmarks on gold bars and other bullion goods

The information displayed on minted or cast precious metal bars differs from that found on coins. With a few exceptions, these rectangular pieces bear no distinctive design or motif. Instead, they carry a series of different stamps and hallmarks indicating their quality and manufacturing source. The manufacturer’s logo is positioned centrally and, depending on the product, this data may also include the country of origin. This is then followed by the weight in grams or ounces, the metal used and its particular fineness, plus the hallmark of the tester or smelter and perhaps a unique serial number.

A serial number can be used to trace the origin of a gold or silver bar at any time. It is also common practice for smaller bars to be issued separately in sealed blister- or foil packaging with an accompanying certificate of authenticity.

The hallmarking of jewellery and watches

Jewellery and watches made from gold, silver or platinum also feature identifying marks. However, because the focus is always on creating a stylish, elegant appearance, these hallmarks are more discreet and thus rarely placed where they can be easily seen. Bracelets and rings usually have a logo and stamp with a three-digit indicator of fineness on the interior surface. Information about the material quality for chains and chain-bracelets is generally found on a flat connecting link positioned near the clasp. Watch hallmarks are usually placed on the underside of the watch casing.

For several years now, it has also been common for jewellery to reference the alloy used in parts per thousand. The alloy content can also be converted into fractional values such as karats (gold) or lot (silver), although markings featuring these values are rarely found on modern pieces.

Here you will find an overview of the most common alloys for gold, silver and platinum jewellery alongside their corresponding karat and lot values:

Gold alloys	Karat	Description/Use
333/1000	8 kt	Alloy with a gold content of 33.3% (gold-plated jewellery)
375/1000	9 kt	Alloy with a gold content of 37.5% (gold-plated jewellery)
417/1000	10 kt	Alloy with a gold content of 41.7% (gold-plated jewellery)
585/1000	14 kt	Alloy with a gold content of 58.5% (dental gold)
750/1000	18 kt	Alloy with a gold content of 75% (jewellery, dental gold)
833/1000	20 kt	Alloy with a gold content of 83.3% (high-quality jewellery)
875/1000	21 kt	Alloy with a gold content of 87.5% (high-quality jewellery)
916,66/1000	22 kt	e.g. bullion coins such as Krugerrand or American Eagle
999/1000 (999,9)	24 kt	Pure gold, almost 100%, common for bullion coins

In Switzerland, the Precious Metals Control Act stipulates that gold must have a fineness of at least 375/1000 or 9 karats before it can be described as gold jewellery.

Silver alloys	Lot	Description/use
800/1000	approx. 13	Alloy with a silver content of 80%
835/1000	approx. 14	Crown silver with a silver content of 83.5%
925/1000	approx. 15	Sterling silver with a silver content of 92.5%
999/1000 (999,9)	16	Bullion silver with a silver content of almost 100%

Platinum alloys	Hallmark	Beschreibung/Verwendung Description/use
600/1000	Pt	Alloy with a platinum content of 60% (simple jewellery)
750/1000	Pt	Alloy with a platinum content of 75% (high-quality jewellery)
950/1000	Pt	Alloy with a platinum content of 95% (high-quality jewellery)
999/1000 (999,5)	Pt	Bullion platinum with a platinum content of almost 100%

Some platinum jewellery pieces only bear the hallmark “Pt” (for platinum) without specifying the fineness.

Precious metal testing of manufactured and imported goods

Precious metal products manufactured in Switzerland or imported into the country are subject to regular checks by approved testers. The checks particularly focus on product authenticity in order to protect consumers from the risk of counterfeit purchases and to prevent unfair market competition. The testing also confirms whether or not the stated fineness is actually correct. To carry out a test, samples of the respective coins, bars or jewellery items can be weighed, x-rayed, cupellated in a high-temperature separation process, or subjected to an acid test. Precious metal testers check over 1.7 million items each year and identify around 2,000 issues involving materials or false descriptions.

How to avoid purchasing counterfeit products

The production of counterfeit or imitation precious-metal products has now become almost as complex and sophisticated as the manufacture of those original items. Bars, coins, watches and pieces of jewellery often resemble the original products down to the last detail. What is of most concern is that they can have an almost identical weight and, thanks to wafer-thin coatings of real gold or silver, they also have a deceptively genuine feel and appearance. However, under that shiny surface all the hapless buyer will usually find is inferior materials such as copper and nickel or even tungsten, a transition metal which has similar weight characteristics to gold itself.

Such counterfeits are sold at prices very similar to the originals, with offers typically set just slightly below official end-customer prices. Almost the only way to expose these kind of fakes is by taking careful note of the sales methods employed. These goods are most likely to be offered in motorway car parks, at secret meetings or in similar locations generally far away from retail stores.

Experts strongly advise against such purchases. The goods have practically no value and cannot be resold. What is more, by trying to knowingly market fake products the sellers are committing a criminal offence. The best and most practical way to avoid such risks is to buy precious metals exclusively from reputable sources such as precious metal retailers, jewellers and goldsmiths. These are also the recommended channels for those wishing to sell valuable precious metal assets.

The hallmarking of precious metals: An overview

Bullion products, jewellery and valuable watches are all marked so the quality of their precious metal can be readily identified, even when there is no packaging present.
Hallmarks and stamps on these items provide information about the metal material used and its fineness, which is given in three or four digits representing parts-per-thousand.
Coins and bars also carry an indication of their weight.
The manufacturer’s logo and the stamp of the tester/smelter allow the value of any material to be easily established and also provide transparent information about the original raw materials used.
In Switzerland, both domestic precious metal products and imports are regularly tested to establish their quality and authenticity.
Today, the best counterfeits are extremely difficult to distinguish from genuine originals, so investors and collectors should only purchase precious metals from specialist retailers.