In Russia, there are metric system assessing the purity of a precious alloy. This determines the assay that corresponds to the weight content of the noble metal, which is the main one in the composition. The higher the amount, the higher the value of the items. An example of this is 958 gold standard.
The alloy differs from the most common (585, 750), it also has advantages and disadvantages. They should be considered when selecting finished products, also take into account the physical properties of the material. On how they meet the conditions of use depends on the duration of use precious metal, his external qualities.
958 gold hallmark - what is it
Items containing more than 30% precious metals undergo an assay procedure. This involves evaluating the content of the components. If you determine the ratio of the base metal to the ligatures, you can find out which group the alloy belongs to. For example, 958-proof gold is in the high value category.
This is due to the content of the precious metal - 958 g per 1000 g. Given this amount, the remaining fraction is determined - it is a ligature (42 g).
Gold 958: composition, how the alloy is called, its properties
Metal with a 958 proof is considered high grade. Given that the percentage is not an integer (95.8%), the number is rounded. This is how the second name of the metal, 96 proof, came about. In reality, the stamp contains other numbers. The 96th hallmark does not belong to any of the world systems for assessing the purity of precious metals.
Pure gold is known for its softness. It is easy to grind, but it is impossible to make a complex shaped piece.
The situation changes when additives are added to the composition:
- copper: 1.2-2.4%;
- silver: 1.7-2.3%.
Sometimes the metal contains other components. In order not to reduce the gold content, the ratio of additives is changed. By reducing the proportion of copper and silver the possibility of using the components appears:
- iron: 0.08%;
- antimony and lead - 0.003% each.
The combination of the ligatures and the base precious metal produces a material with different properties:
- The strength of gold 958 is a relative concept, if you compare it to pure precious metal (999), the products are harder, more wear-resistant, and when compared to gold alloy 750 or 585 It turns out that the 958 material is not used much, but this metal can withstand moderate loads, which allows its use in several areas, including jewelry (making simple jewelry, wedding rings);
- Density: the precious metal is quite soft, the density is 18.5 g/cm3It's not always easy to process products because of this;
- Inertness: the metal does not react with various substances from the environment, it retains its shape, structure and properties, but it may darken;
- melting point: 958 gold melts when heated to 1030 ° C, under normal conditions (at room temperature) does not change with the metal.
Table: Impurities and range of shades
Color alloy gold is always the same because the metal contains a small amount of ligatures. Even changing their ratio has no significant effect on the tone of the material. To understand how much additives can change the color of a precious metal, you can study the table:
|Color||Au75%||Au75%||Au 58.5%||Au 58.5%|
|Ag, %||Cu, %||Ag, %||Cu, %|
Why you should not confuse pure gold with noble gold
The alloy used today (gold 958) can be called high alloy (pure metal 999 proof). But there is a difference between them - the content of the ligature. Originally, gold without additives was called niello. Later another definition appeared. This was the name given to products made from red-colored alloys.
So, the material 958 does not meet the parameters of either type of metal (pure, red), and therefore cannot be considered niello.
In Soviet times, products were marked with a special mark - a five-pointed star. Before that, there was another brand in the form of a worker's head with a hammer, and even earlier, the profile of a woman's head in a kokoshnik. After the collapse of USSR have returned to this type of labeling.
The woman's head is in a figure of a complex configuration resembling a spatula. Here are also the numbers of the hallmark, and together with it, the state assay office's code number, and the mark of the assay certificate. If the piece has a different stamp, this could mean that it was made in another country.
When imported into the Russian Federation, such items are subject to assaying, according to the law.
How many carats are in the 958 sample
Earlier in the USSR it was used spool system The purity of the precious metal. Today jewelers have moved away from it. According to the law, the metric system is relevant. But if the need arises, it is always possible to convert the sample to either system:
Spheres of application in the USSR and now
Previously alloy 958 was not used everywhere. It was used mainly in the production of certain types of products. It was created:
- engagement rings;
- decorative inserts.
Today, gold alloy is also not characterized by a narrow field of application. It is almost never found on the open market. Most often products are created to order. The main areas of application:
- making small-thickness gold leaf coatings;
- furniture finishing;
- decorative inserts and whole ornaments that have little contact with the leather, thus reducing the intensity of wear and tear.
Compatibility with stones
The precious metal containing 95.8% of gold does not allow for the creation of miniature jewelry. Because of its massiveness, the stones only worsen the appearance of the pieces. In addition, the metal is quite soft, and therefore it is problematic to fix on ringThe bracelet has stones on it. This can be done if you want, but the strength of the attachment will be low.
Such pieces are made to order. The alloy is better matched with diamonds; garnet, agate, and ruby are used less frequently.
Reaction of sample 958 to gold chloride
To check the authenticity of the precious metal, sometimes materials, substances of aggressive action are used. Among them is chlorine gold. In contact with it, the precious metal changes color. But if it contains a significant proportion of Au, the nature of the stains will be different than in cases where this component is not contained in the alloy.
The presence of gold leaves lighter stains. The less of it, the darker the stains.
Pros and cons of 958
If you want to buy a finished product with a high content of gold, you should consider the advantages and disadvantages of this metal, so as not to regret the purchase.
Alloy 958 gold jewelry is distinguished not only by its volume, but also by its mass. It is usually greater than other items that have been made from other types of materials.
Actual price of 1 gram of gold according to the Central Bank
The Central Bank of Russia provides daily updates on the 999 gold exchange rate. The price of other items depends on it. But the price of pure gold is constantly changing. To buy/sell items made of different alloys in the most successful way, it is necessary to keep track of information about changes in the price of the pure metal.
|Precious alloy 999 tests (TsB), 1 gram||Market price||Scrap, rub.|
Calculation of the cost of 1 gram of 958 gold
To determine for yourself how much is the price of gold alloy in a certain time period, you need to take as a basis a formula:
Central Bank exchange rate of the metal 999 x 0.958 = price of the alloy with the given parameters,
The result is: 4450 x 0.958 = 4263 rubles.
Tips for the care and cleaning of fine gold
A metal containing 95.8% gold needs special care because abrasion can damage it. This alloy is most commonly used to make jewelry without stones, which makes it easier to clean it. Key recommendations:
- It is necessary to exclude contact of the precious metal with cosmetics, hot water, sweat, which means that during showering, sports, physical activity should not wear jewelry;
- You should periodically clean your gold jewelry with a soapy solution and a soft rag;
- Do not keep gold-alloy 958 items near others, it may cause scratches;
- Do not use abrasives: baking soda, tooth powder or a toothbrush.
Important: The possibility of tarnishing of a metal containing 95.8% gold is low due to the small amount of ligatures, but it is still better to avoid contact of this material with household products and other chemicals (perfumes, cosmetics, etc.).
Question and answer section
What causes gold to oxidize?
What are the reasons for the darkening of gold?
- Poor quality of the ligatures or inconsistency of the composition with the stated characteristics;
- residual polishing paste on the new product;
- material's interaction with chemicals.
Why does gold leave marks?
Why and where to buy 958-proof gold. How to buy it and sell it profitably
- Internet resources (Avito, etc.);
But to check the certificate in this case is not possible, which means that the risk of buying a fake is too high. It is better to look for opportunities to sell or buy the product in official stores. To sell the product profitably, you need to prepare it: clean it from dirt, grease film, perform grinding.