Any buyer purchasing a gold piece wants to be sure of its quality. Sample is a kind of guarantor that confirms it. Over the centuries, each state has tried to develop its own assay system, and only relatively recently has it been possible to standardize methods for determining the amount of gold.
In modern language, the fineness means the amount, the percentage of gold in a particular piece of precious metal (this is gold, silver, platinum). In the world at different times, various methods of marking the amount of precious metal in alloys were used, however, the most famous are 3 types of sample systems.
Zolotnikovaya (Russian)
In Russia and the Soviet Union, up to 1927, Russian was used, it is also a spool test. The essence of the system is that the amount of pure gold, silver in a pound of alloy was determined by spools, more precisely, by their number. It is worth recalling that the spool is an old Russian unit of mass equivalent to 1/96 pound, or approximately 4.266 g. 1 pound of pure gold, silver equals 96 spools. Hence it follows that the pure metal is the 96th test. If the sample was, for example, the 72nd, then the pound of the product contains 72 full-weight spools of pure metal, and 24 spools - additives (ligature). Today, the spool sample system is not used, but jewelry with similar markings can be found.
Karat
The British carat system is used, in addition to England itself, in Switzerland, the USA, and some other states. In accordance with the carat type of samples, 1 carat corresponds to 1/24 of the weight of the alloy. Those. the purest will be 24K gold (twenty-four carat). If a product made of a gold alloy has the designation 18K, then this means that it contains 18 parts of pure precious metal, 6 parts - a ligature. Jewelers practicing the carat system use 18K, 14K, 10K and 9K alloys.
Metric
The metric system is considered the most accurate, and it is used in most countries of the world. According to the metric system, the purest (ideal) gold is considered to be 1000-carat gold. However, in this form, gold is used only in chemistry and for the manufacture of ingots (the country's gold reserve) - pure metal is soft, brittle, it is not suitable for making jewelry. Therefore, in practice, marking is carried out with three-digit numbers. Because It is difficult to achieve an ideally accurate content of pure metal in a product, then a remedium is used (deviation from the norm). If the jewelry is made of an alloy, which, in addition to gold, includes silver, copper, or both of these metals, then the remedium will be equal to three units. For example, if you have a 583-carat product in your hands, it means that the percentage of gold will be equal to 580-586 units (or 58-58, 6%). If the alloy contains nickel, then a remedium of 5 units is allowed.
