Frequently Asked Questions | Goldanalytix

Here you find answers to the most frequently asked questions on all topics related to precious metal testing. The questions and answers are neatly arranged according to key topics - so you can find what you are looking for very quickly.

Technical terms

What technical terms are there in precious metal testing?

Alloys are mixtures of mostly two or more metals. Well-known alloys in the field of precious metals are, for example, red gold (gold-copper), white gold (gold-palladium-silver) or yellow gold (fine gold-silver-copper).

Ingot refers to molten metal cast into a standardised shape to make it easier to transport and process.

Blister/blister card:
A blister is a transparent type of packaging, especially for bars of all kinds. The bar is usually placed in the middle of the blister card, which protects it on the one hand and also presents it attractively. The packaging allows the bar to be viewed from both sides.

The purity (fineness) of gold is expressed in carats.
Example: gold 585 denotes an alloy with a gold content of 583 1/3, this would correspond to 14 carats; fine gold 999 denotes gold with a content of 999 in 1000, this corresponds to 24 carats.

Curant coin:
This is the description given to coins whose nominal value is (almost) completely covered by the metal of which they are made. This contrasts with the sheath coin.

Divisional coin/token coin:
This is the name given to coins whose nominal value is not covered by their metal value.

Electroplating is the term used to describe a surface finishing technique.
Two uses: Functional electroplating (e.g. protection against corrosion/wear), decorative electroplating (chrome plating). Counterfeiters use this technique to make tungsten cores look real.

This expresses the percentage of a precious metal in a coin or bar. The fineness is expressed in parts per thousand.

Gold standard:
The gold standard refers to a monetary system commonly used in the past where gold was the main factor in the currency.

An embossing of precious metals is called hallmarking. Often the fineness of the material is hallmarked.

Investment gold:
EU-Directive: "Gold in bar or plate form of a weight accepted by the gold markets and of a fineness of at least 995 thousandths [...] or gold coins of a fineness of at least 900 thousandths." For gold coins, it is also crucial that they were minted after 1800, are or were legal tender in their country of origin and are sold at a price that does not exceed the market value of their gold content by 80%.

Ounce/fine ounce:
An ounce is a unit of measurement for the mass of a wide variety of objects (e.g. common ounce, fluid ounce). In the context of precious metals, the troy ounce is used, which is approximately 31.10 grams.

A refinery is a company that separates different metals from each other and recycles them. The end product is a precious metal that is as pure as possible, which can then be sold on.

Methodological terms for measuring precious metals


  • Density of a body describes its mass in relation to its volume
  • "Pseudo-density" can be calculated from the dimensions and weight of the object at hand
  • Each material has a specific density


  • Conductivity is the ability of a substance to transfer energy (e.g. electricity, heat)
  • It is measured in megasiemens per metre
  • Our devices measure conductivity using inductive eddy current measurement


  • Diamagnetism = the occurrence of a magnetic field (magnetisation), when an external magnetic field is applied to a substance, whereby the magnetisation opposes the external field. Summary: diamagnetic materials are repelled by the magnet.
  • Paramagnetism = form of magnetism in which a substance shows no measurable magnetic moment in the absence of an external magnetic field, but acquires a magnetisation in the presence of an external field. Summary: Paramagnetic materials are slightly attracted to the magnet.
  • Ferromagnetism = By applying an external magnetic field, the elementary magnets align themselves in the same direction. The ferromagnetic material itself becomes a magnet. Summary: Ferromagnetic substances are attracted to the magnet.

Susceptibility properties:

  • Describe the ratio of the magnetisation of a material to the magnetic field strength
  • This so-called magnetic susceptibility can be measured with the help of a magnetic balance
What does the carat number on my gold stand for?

For diamonds/gemstones, carat is a measure of weight. Here, one carat corresponds exactly to 0.2 grammes. In the precious metal trade, on the other hand, the gold content of bars and coins is indicated as the fineness or fine gold content, usually in the form of an embossing. The CaratScreenPen measures the carat number of gold within seconds. Pure gold bars are stamped 999.9, also known as "four nine fine".
Below you will find an overview of the carat specifications for gold:

8 Karat:
Gold 33.3 %

9 Karat:    
Gold 37.5 %

10 Karat:
Gold 41.7 %

14 Karat:
Gold 58.5 %

18 Karat:
Gold 75 %

20 Karat:
Gold 83.3 %

21 Karat:
Gold 87.5 %

22 Karat:
Gold 91.666 %

24 Karat:
Gold 99.9 %


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