Due to the natural physical and chemical characteristics, gold has found application in many areas: jewelry industry, chemical industry, medicine, dentistry, etc. Clean precious metal is soft, malleable, which makes it lose its jewelry value. Manufacturers use an alloy of different metals, which increase the strength, durability, improving the consumer properties of products.
The ligature composition is very diverse, defines a wide range of gold products.
Ligature and ligature gold - what are they, auxiliary alloys, what applies
Most of the mined metals initially contain unnecessary components. After extracting the reserves from the earth's crust, the raw materials are processed for further transportation. Dore alloy is made from mined ore that is saturated with various elements. This form allows the future noble metal to undergo refining at specialized plants, where it is purified of impurities.
Pure precious metal itself is quite malleable, which makes it unsuitable for the manufacture of various objects.
However, ligature gold is highly prized by jewelers. The addition of other elements can change the physical properties of precious metals, improve their wear resistance and appearance.
A ligature involves mixing together pure metals without any impurities. Several refined components can be added to the precious metal at the same time: copper, platinum, silver. The composition is characterized by strength, malleability, which is important in the manufacture of jewelry.
Historical fact of the appearance of the ligature in the monetary system
As early as the Middle Ages the noble metal's physical characteristics led to the search for methods of increasing gold's hardness. Coins made of pure precious metal lost their weight over time and became deformed. That's when ligature for gold appeared in the monetary system, allowing to prevent coins from rubbing off thanks to addition of non-ferrous metals.
Such a decision caused differences between the images on the coins and their real composition. This difference began to be noticed by "money changers" of the time, who checked the authenticity of coins by rubbing them against a rug. Pure gold money shrank and lost weight, while the mat accumulated a large quantity of noble metal.
Gradually, the full-weight coins in circulation ran out, leaving only the incomplete ones. There was a depreciation of the old means of payment.
The metals that determine the color of gold
The color directly depends on the composition of the jewelry and the proportion of impurities:
- white hue hallmark 585 - result of alloying with the base metal of nickel, palladium, platinum, silver, the fraction of the noble metal is about 59%;
- red The tone is given in the composition of copper;
- yellow The shade of the product is characteristic of pure metal with a slight addition of silver or copper;
- The purple shade is the result of mixing the precious metal 750 samples with aluminum;
- black colorThe alloying metals are ruthenium, chromium, and cobalt;
- green tint is obtained by adding silver and rubidium.
The hallmark is the same, but the color of gold is different
Products different colors can have the same sample due to impurities. The proportion of the base metal remains the same, only the proportions of the ligatures change. The lack of bright luster in a gem may indicate the presence of nickel among the constituents. Copper can be added to give a yellowish hue.
The amount of additives not only allows a variety of colors, but also significantly increases the strength of the material, as well as protect it from external influences.
Palladium and platinum are precious ligatures that increase the value of a gold piece
The most expensive precious metal alloys are platinum and palladium. This gold ligature is not available to every customer because of the high cost of jewelry. The price of such a composition is considerably higher than that of other precious metals and is equivalent to items made of pure noble metal.
Top 4 gold assay measurement systems
- Spool. Refers to obsolete measurement systems USSRThe base is the Russian pound, consisting of 96 gold pieces. The basis is the Russian pound, consisting of 96 gold pieces.
- Metric. This is the system most often encountered by buyers. The assay on jewelry indicates the proportion of gold in the alloy. This indicator helps to determine how good the quality of the product. The price depends on the hallmark.
- Carat. Indicates the gold portion in the carat ratio. Applies to Western Europe and North America. Essentially resembles the metric system of measurement.
- Lot. Measurement System. gold gradeswhich was used in Germany until 1888. Using the system it was possible to determine the number of lots of gold in the existing 16.
Table: Sample ratio between systems
| Part of pure precious metal | Metric system, Sample | Carat system, carat |
|---|---|---|
| 99,9% | 999 | 24 |
| 95,8% | 958 | 23 |
| 75% | 750 | 18 |
| 58,5% | 585 | 14 |
| 58,3% | 583 | 14 |
| 50% | 500 | 12 |
| 37,5% | 375 | 9 |
What the sample means and how it is deciphered. The metric system of measuring samples in Russia. The main gold alloys
The percentage of pure gold in a ligature can be determined by the assay. Each precious metal item, even if gold-plated, is stamped with a number. The marking also indicates the alloying components of the jewel.
The following samples are used in Russia:
- 375 is characteristic of low-grade items consisting of 62.5% of a mixture of silver and copper. The rest is made up of precious metal.
- 585 - can include several composition options:
- The alloy consists of gold (58.5%), copper (33.5%), and silver (8%). This composition is highly durable and has a characteristic reddish or yellow tone. It melts easily, flattens out, and does not oxidize in contact with air.
- Includes gold (58.5%), nickel, palladium (41.5%). The resulting alloy is white, does not tarnish, and is easy to solder.
- 750 - the metal is strong, hard-wearing, but soft. Such items require careful use and proper care. The content of pure gold is not less than 75%:
- The gold-silver compound 25% is an electrum, found in nature, and has a distinctive greenish tone.
- The proportion of 21% copper and 4% nickel impurities gives a reddish hue.
- The composition includes 15% silver, 10% copper, the usual yellow color.
- 958 consists of 95.8% gold, 4.2% a mixture of silver and copper. The alloy turns bright yellow and is almost never used by jewelers because of its increased softness.
- 999 - includes only 1% ligatures. It is used for bank bullion.
Imported gold-plated ligature price per kg
Most often, foreign jewels differ from domestic ones in their assay. Their ligature content exceeds the quantity of noble metals. American and European standards have some similarity with Russian ones, but the assay mark is given in carats. It is often possible to buy a fake with a precious coating.
Low-carat gold is very popular abroad for jewelry making because of its more suitable consumer characteristics. 9 to 12 carat is much stronger and harder, and is characterized by high resistance to deformation and scratches. In Russia, pieces with fewer impurities are more popular: the higher the carat, the greater the demand.
Turkish gold is marked with three digits 585. There are no other designations. A large proportion of the ligature is copper, which can be determined by the excessive redness of the pieces. It is not uncommon to pass off gilded silver items as jewelry. Jewelry tarnishes and deforms over time. However, it is still highly sought-after due to its affordable price.
There are also Emirati jewels. They contain a minimal amount of ligature. Only two 916 and 958 proofs are used. The jewelry is short-lived, so in the country it is customary to wear it only at weddings. From then on, the jewels are simply kept in caskets.
Is there a ligature in the gold bars
Gold bars are referred to as 999 proof gold bullion. This means that the product contains 999 grams of pure gold and 1 gram of impurities per kilogram of product. They are used for investment purposes and are prized all over the world.
In what areas the ligature is used
The additive is intended to improve the physical, chemical characteristics of the precious metals. The metal additive is introduced when the base is cooked, making it refractory. In the process of adding the ligature, experts take into account the loss of metal that occurs during melting. This means that the proportion of impurity is directly related to the volume of precious metal after "loss". Alloys are used in many applications because of their physical properties:
- Jewelry craftsmanship. All GOST alloys are represented by alloyed metals. The assay with the minimum allowable amount of gold is 350, which contains only 35%, is not used for jewelry. However, it is possible to find jewelry of 375 hallmark. The most popular is 585 red gold. The alloy includes 58.5% of the precious metal, 20% of copper and other impurities. Such items are distinguished by their scarlet tone. It is possible to work with scrap gold in the jewelry industry because of the ligature.
- Musical instruments. Ligatures are used in saxophones and other instruments. The ligature is found on the part that attaches to the mouthpiece. The precious alloy part reduces air loss, making the sound particularly colorful, extended.
- Dentistry. There is a special ligature alloy for dental braces, which is used to bind the metal and plastic parts that are attached to the teeth.
- Medicine. Ligature thread is used by surgeons to ligate severely damaged vessels.
- Tech manufacturing. Many of today's gadgets are manufactured using durable ligature. Electrical connector, microcircuits, contacts are covered with ligature material.
Video: jewelry making and alloying
Jeweler's opinion
