Silver is a precious metal that, like other types, must have a purity. In this case, the sample designation is used in order to show the composition of a particular metal alloy.
Silver, like other precious metals, in Russian jewelry practice is usually marked with a special designation, which is called a sample.
Most precious metals in their pure form are not very convenient for use, including in the jewelry industry: they are too soft, bend easily and, accordingly, quickly lose their aesthetic properties. Therefore, it is customary to combine them with various additives that improve their quality. Accordingly, silver used in jewelry making, like other precious metals, is actually an alloy of pure silver with other metals.
The ratio of the precious metal and additives to it in the composition of such an alloy is usually denoted by breakdown. Basically, a fineness is a marker indicating the content of pure precious metal in a particular alloy. There are five main types of samples in the Russian jewelry industry. The lowest - 830 fineness, means that the composition of this alloy contains 83% silver and, accordingly, 17% of other metals, which are usually non-precious.
Other tests that can be found on the jewelry market are 875, 925, 960 and 999. As follows from the very concept of a test, 999 is the highest: it contains 99.9% pure silver and only 0.1% impurities.
Composition of 925 sterling silver
925 sterling silver is most often used for the production of jewelry, since it is characterized by the most practical combination of pure silver and impurities, providing the alloy with ease of use. The 925 test means that this alloy contains 92.5% silver and 7.5% additives.
Copper is usually used as an additive to silver of this sample. It gives the alloy a high level of strength, which allows the product to be used for a long time. Such a sample of silver is also called sterling or simply "sterling", since it was this metal that was used to cast silver coins in England, which is additional evidence of its high wear resistance. At the same time, the 925 sterling alloy has significant plasticity, which makes it possible to make a wide variety of shapes from it, creating unique jewelry.
Experts in the field of the jewelry industry are trying to add other types of impurities to silver, but the results of such experiments show that the finished alloy in this case is either inferior to sterling silver in its properties, or becomes too expensive, as, for example, when platinum is added to silver. Therefore, today it is the silver-copper alloy that is considered the standard of 925 sterling silver.