Among all jewelry, 750 gold is now very popular. The gold content in the alloy is higher (75%), because it is considered more prestigious. But at the same time, jewelry will require a careful attitude from its owner, since such an alloy is softer in comparison, for example, with products made from 585 gold .
Gold jewelry was valued at all times. This is the oldest precious metal. In the excavations of ancient pyramids and mounds, unusually beautiful and valuable gold ornaments are found. Thanks to its brilliance and color, this precious metal has always been considered the embodiment of the sun, which people worshiped during paganism. Gold jewelry identified power and power. Thanks to "proximity" to the pagan deity, gold was endowed with extraordinary healing properties. It was believed that this metal will help get rid of epilepsy, heart attacks, inflammation of the heart muscle and other diseases associated with the heart. Perhaps, this explains the Catholic tradition - the wedding ring of gold worn on the left hand.
What is gold?
It is a highly plastic and very soft metal that does not oxidize in air, is resistant to moisture and is immune to the influence of salts, alkalis, acids. Pure gold is used in the jewelry industry for the production of precious metal alloys. Gold alloy is an ideal material for the production of jewelry. Gold in its pure form is very soft, and alloys from it are more wear-resistant and durable. To enhance the hardness of the metal, it is mixed in certain proportions with other precious and less valuable metals. The sample of jewelry jewelry expresses the amount of gold (pure) in the alloy.
What is 750 sample of gold?
This alloy contains 75.5% pure gold and additives, or so-called ligature. Depending on the additives introduced into the alloy, the products can be of different shades - yellow, white, green, pink, red and even brown or black. The most popular gold is 750 samples. Products made of it can be made the most exquisite. The alloy can be easily polished and processed. Decoration from such gold is a real work of art. From it, earrings, bracelets, chains, engagement rings are made. Gold 750 color is more approximate to the color of pure metal in comparison with the samples below. However, when changing the composition of impurities, alloys can be obtained from the same sample, but the color will differ.
In the European countries, a carat system is adopted, in which 24 carats indicate a perfectly pure gold of 1000 samples, but it is impossible to obtain it. Therefore, pure gold is considered to be 999 ("three nines") gold. 22 carats corresponds to 917 samples, 18 carats to 750 samples, 14 carats to 585 samples, 10 carats to 417 samples, 9 carats to 375 samples.
Gold composition of 750 samples
The composition of gold alloys in Europe and the former CIS countries are slightly different. Gold 750, as a rule, is three-component and contains silver and copper, rhodium, palladium, nickel, zinc can be added less often. We have more copper in alloys, in Europe - silver. Due to this, our gold has a pronounced reddish tint, the European one is more yellow. Gold 750 samples, in which the content of copper is higher, is characterized by high strength.
To enhance the hardness, palladium or nickel can be added to the alloy. Palladium is a very precious precious metal. Thanks to him, gold acquires an exquisite soft shade. The cost of jewelry, having such a composition, is high enough, they are suitable only for real connoisseurs of precious jewelry. The price of products with nickel is much lower, such an alloy can be magnetized.
To achieve high performance characteristics, the method of vaporization of metals can be used. The solid solution in this case decomposes into different phases and the AuCu3 is separated.
Gold of 750 tests perfectly shows itself during processing, casting, joint adhesion. Also, when working with vitreous enamel, the alloy can serve as the basis. However, it should be borne in mind that the content of copper in the alloy should not exceed 16%, otherwise the quality of the enamel will deteriorate, and after a while it will lose its brightness and beauty.
Semiprecious and precious metals in alloy composition
Depending on the metals included in the alloy, it can be white or colored. The appearance of the product and its technological characteristics are directly influenced by the percentage of impurities of copper and silver in the alloy.
The alloy of gold and silver has a lemon tinge. The alloy of gold with copper is characterized by a pinkish or red color. The melting point of gold and silver is one thousand degrees, with copper - a little below nine hundred. When cooling, a solid, homogeneous mass is formed, which then decomposes into phases.
According to the chemical ratio of the elements, the alloy of 750 samples is practically pure gold. If you compare it with gold of 585 tests, then such alloy is much better amenable to any treatment.
Even repeated heat treatment does not affect the strength of the gold alloy of 750 samples with the content of copper and silver. Spontaneous cracking of precious metal does not occur.
Gold of 750 tests is prestigious and noble. Jewelry from such an alloy is highly valued all over the world. Jewelry from him is always relevant and not subject to fashion trends.