It may sound a bit of a surprise, but the jewelry is not made of pure noble metals as in their original state they don’t often have the necessary properties. For instance, gold is too soft to work with. To give them the necessary mechanical properties and a wishful color nonferrous metals are brought into. Thus, we get different alloys, for example, that of gold with silver and copper, sometimes with palladium, nickel, zinc and cadmium.It is the precious metal content that determines the mark of quality.
In the USA, Britain and Switzerland the carat system is used. According to the carat system the 1000th mark of quality of the precious metal corresponds to 24 conventional units. In most European countries the metric system of the mark defining is used. It means that it is defined by the number of parts of the precious metal in 1000 weight units of the alloy.
The quality mark of precious metals alloys is set legislatively and is guaranteed by the state. All the jewelry necessarily undergoes the assay control to ensure it. As a result the mark of assay is put. The mark is defined by its digits. It’s up to a country to choose the form and the pattern of the mark of assay.more...