Silver is one of the earliest precious metal materials used for currency circulation. With the development of the jewelry industry and changes in consumer attitudes, the silver jewelry market is getting bigger and bigger. Its features are as follows:

1. The specific gravity of silver is medium (10.5), the melting point is 960.8°C, and the hardness is 2.7.

2. The chemical properties of silver are more active than gold and platinum. Insoluble in dilute acid, but soluble in concentrated nitric acid and agro-sulfuric acid, and also reacts with sulfide, halide, cyanide, sulfite, etc.

3. The ductility of silver is good, the thinnest silver foil is 2.5um, the malleability and plasticity are good, and it is easy to weld and polish.

4. Silver is silver-white and has the highest reflectivity of all metals.

According to the provisions of the national standard (GB/T1689-93), silver is divided into two categories:

Pure silver—that is, silver with a thousandth of silver content not less than 990;

925 silver - that is, the silver with a thousandth of silver not less than 925, and the other thousandth of copper is 75.

The most common in the jewelry market is silver with a silver content of less than 990 per thousand, and its hardness and ductility are the most suitable for making jewelry. The complementing elements of this type of silver are generally copper, zinc, tin, etc. .