What is a gold assay

Gold assay is a marking that indicates the ratio of pure gold and impurities in the alloy. The fact is that 100% gold is a very soft material. So much so that it can be crushed with fingers. Therefore, in jewelry and a number of other industries use an alloy of gold with ligature (additives). As a ligature can be used:

• Copper. It gives the gold a hardness and a red tint. This variant of the alloy was especially popular in the USSR, the so-called “red gold”.
• Zinc. Increases the fluidity of the material, at a certain percentage in the alloy can give an emerald hue.
• Platinum. Increases the melting point, gives gold a special glow.
• Silver. Increases casting properties, gives hardness to products and makes gold lighter in color.
• Nickel. Makes the alloy harder, protects against corrosion. Gives a lighter color to gold.
• Palladium. Increases the melting point, makes the metal more ductile. The alloy is characterized by a light shade.
• Cadmium. Increases casting properties, can give a green tint to gold.

The numbers, which describe the assay, denote the ratio of parts of gold to parts of additives. It is worth noting that there are 4 systems for determining the purity of gold. The most popular are metric and karat (used in Europe and the USA).

With the metric system everything is as simple as possible: it shows how much gold was used per 1 kg of alloy. For example, if 585 grade is specified, it means that 585 grams of gold and 414 grams of ligature were mixed in the production of the alloy.

The karat system keeps track of the ratio of gold to 24 parts of the alloy. That is, 24k is pure gold. And 12k will correspond to 500 proof in the metric system. For convenience, here is the sample conversion table below.

The most popular gold grades

According to GOST R 5Z197-2008, according to which gold products are marked, only 7 grades are officially recognized in our country.

585 proof

The most common is 585 grade of gold. The fact is that it is at the mark of 58.5% it was possible to obtain an inexpensive, but at the same time beautiful and functional material. Products of 585 grade are convenient for daily wear: they are not deformed, are not subject to scratches, retain their shine for a long time, do not darken over time and do not dye the skin. For example, a wedding ring, which is rarely removed when doing housework, can easily withstand repeated daily contact with water and detergents. At the same time, the plasticity and strength of 585 gold allows you to make jewelry of any design.

750 grade

Less common because of its high cost. But it is considered by jewelers to be the “reference” grade: it has the best casting properties. 750 proof is used most often by famous jewelry houses for making elite jewelry.

375 proof

Economical variant of gold. The low content of precious metal makes such products available to a wide range of buyers, and at the level of processing – adds to their rigidity. But, unfortunately, 375 grade jewelry quickly loses its luster.

Where to see the gold grade on a piece of jewelry

To read the proof, you will need a magnifying glass: the size of the mark is very small. As a rule, the mark is located in an inconspicuous place: on the inside of the ring, on the clasp of earrings in pusetas, on chains – on the clasp or ring next to the clasp.

The marking contains:

• Letter. It denotes the code of the state inspection of assay supervision.
• The ideogram of the assay certificate. In the Russian Federation, it is the profile of a girl in a kokoshnik. On Soviet jewelry was a star.
• The digit of the assay in the metric system.

The mark is applied by laser in the Assay Chamber. From January 1, 2021 all jewelry will be subject to marking, and from July 1, 2021 the sale of unmarked jewelry will be prohibited. According to the idea of the regulatory authorities, this should protect buyers from counterfeits and counterfeit jewelry entering the jewelry market.