Hallmarks and carats: how to recognize the purity of gold and silver


Anyone who deals with the subject of precious metals cannot avoid the terms hallmark and carat. These usually indicate the fineness of gold or silver and quickly determine it's value.

In this article we explain how exactly the system of hallmarks and carats works and why standardized hallmarks are useful for the national and international gold trade.

What is a hallmark?

If you use or hear the word hallmark, you have to make a fundamental distinction between two meanings. A hallmark is usually the stamp that indicates the fineness of the gold or silver on a piece of jewellery or a bar.

However, the tool with which this gold and silver stamp is stamped into the precious metal is also called a hallmark. This tool is a hammer, which is put on the precious metal piece and leaves the respective embossing by a blow.

According to German law, there is no obligation to stamp the precious metal with the fineness of gold or silver. The punching does not necessarily have to be done, but it is recommendable, because this way the fineness is visible at a glance. Further testing of the fineness is therefore not necessary in the first step.

If a piece of gold or silver is marked with a hallmark, this must be done in accordance with the law on the fineness of gold and silver goods.

This regulates, among other things, that

- hallmarked gold must have a fineness of at least 585 or more thousand parts, and

- silver must have a fineness of at least 800 or more thousand parts.

This ensures that a certain value can be assumed for punched precious metals.

In addition, a maximum error limit of 10 parts per thousand is permissible for the stamped hallmark. This corresponds to a deviation of one percent between hallmarking and real fine gold content.

The difference between hallmark and carat

The terms hallmark and carat are actually only different units of measurement for determining the fineness of gold and silver.

The number indicated by the hallmark indicates the fineness in relation to the total weight. The calculation here is in thousandths of a second. In the case of a piece of gold jewellery, this means that a fine gold content of 833/1000ths is indicated for a hallmark with the number 833. This results in a fine gold content of 83.3 % for this piece of jewellery.

Based on the weight, the exact gold content can be calculated. If the piece of jewellery in this example now weighs 100g, the exact gold content is 83.3g.

As described above, the designation in carat is only another designation for the fineness of gold and silver. In the following list you can read the carat numbers belonging to the respective hallmarks.

Alloys - What are they?

If there is no gold content of 99.9% in a piece of gold jewellery, this is referred to as an alloy. Alloys are compositions of different metals that are brought together during the melting process.

Even if pure gold or silver is of course the most valuable, gold or silver alloys are used predominantly in industry as well as in jewellery production. This is because the pure precious metals are often too soft.

For example, gold necklaces with a fineness of 99.9% would easily tear. For this reason gold and silver are enriched with other metals. These alloys are harder and therefore more resistant. Furthermore, alloys are also used for colour changes of the precious metals. Also much more favorable pieces of jewellery can be manufactured in this way.

Significance of hallmarks and carats on the market

For the worldwide trade, hallmarks are of great importance. By indicating the fineness, silver bars or gold bars, for example, can be traded more easily. If these bars are traded by reputable suppliers, an exact check of the fineness can be dispensed with.

With regard to international trade, however, a special feature should be taken into account, especially in the case of gold. For example, the definition of gold in different countries is linked to purity. In Great Britain and Switzerland, gold is only referred to from a hallmark of 375 (9 carats). In the Netherlands even only from 585 (14 carats). In the Middle East and Asia it should also be noted that often only almost pure gold with a content of over 22 carats (91.6%) is really interesting.