Gold alloys: types, composition and colors

In jewelry production, the use of precious metals in their pure form is not always advisable, because many of them are not sufficiently hard and wear-resistant. To remedy the situation, it is customary to add other metals to them, creating alloys.

As for gold, some doctors are of the opinion that it has healing properties, while esotericists attribute mystical characteristics to it. Be that as it may, different metals have long been mixed with pure gold, as a result of which various alloys have arisen.

Pure gold is a soft yellow metal, its hardness can be compared with the hardness of a nail, and therefore jewelry and any products made of pure gold are difficult to imagine in everyday life, they would be too fragile.

Ligature gold is an alloy of pure metal with other elements. Most often, silver, platinum, copper, cadmium and other elements are added to gold, on which the final shade of the metal and its properties largely depend.

When silver is added to gold, it becomes even softer, with the final color ranging from light yellow with a tint of green to white. The higher the silver content in the alloy, the lighter the metal will be in the end.

Copper is very often added to gold, which makes the metal harder and more wear-resistant, but depending on its concentration, it can give gold a red tint. But it is greatly appreciated.Gold mixed with copper is often called red.

The presence of zinc and cadmium in the compositiontends to make gold more fragile. These alloys are not used in jewelry.

Alloy of gold and palladium allows to obtain the white color of the metal, as well as to preserve its malleability and basic properties.

Gold and nickel - this alloy increases the hardness of gold and basic casting qualities, but at the same time the metal acquires a noticeable yellowish color.

An alloy of gold and platinum is obtained with a shade of white. The white color turns out to be even richer than if palladium was mixed with gold. This ligature has high anti-corrosion properties, and therefore is in great demand.

It is known that the ligature gold and titanium 4 times harder than pure titanium. This alloy is used mainly for medical purposes.

And here an alloy of gold and aluminum in terms of external qualities is practically indistinguishable from pure goldbecause it has almost the same color. It is impossible to detect the alloy with the naked eye. Copper-aluminum alloy also difficult to distinguish from real gold in color. This alloy is called "French gold".

Scientists have also obtained alloys gold and iron, but they also proved that they rust very quickly, and therefore do not enjoy wide popularity. And there is no special need for them: iron in itself does not improve the properties of gold. However, in very rare cases, a 750-carat gold and iron alloy can be used, which has a bluish tint, but this color is only superficial, it wears off quickly, and is also prone to corrosion and finds little approval from jewelers.

To obtain an expensive and luxurious shade of blue, steel, indium or gallium are added to gold. Depending on the metal and its proportions, the shade is more or less intense.

Despite the fact that everyone is used to the fact that the color of gold is yellow, there are also other shades of it, depending on the impurities in the metal.

• Yellow. The classic version of gold jewelry is yellow and its shades. Typically 585 and 750 are used for this color.

• Black. The black tint of gold can be obtained in several ways. Most often, the metal is oxidized with cobalt, patinated or coated with rhodium, sometimes ruthenium.

• White. This color of gold can be obtained by creating a variety of alloys - here and palladium, and nickel, and platinum. The latter metal is now used extremely rarely, since the mixture is very refractory.

• Red. The redness of gold depends on how much copper is added to it. In intensity, the shade can be pink or deep yellow. The widespread popularity of red metal is reflected in the creation of wedding rings.

As for other shades, there are such types of gold.

• Blue. It is considered unique and very rare, many do not even know about the existence of such a ligature.

• Yellow-green. This shade is obtained if silver or cadmium are added to it. It is not recommended to wear such jewelry for a long time, as it is believed that they can negatively affect health due to their toxicity.

• Purple. For a long time, the creation of such a shade seemed to be something impossible. But it turned out that the purple tone is easy to obtain if you add aluminum and palladium to gold in the right ratio. In this case, the metal will be delicate and fragile, and therefore can only be used to decorate individual parts of jewelry.

Not everyone can afford to buy expensive gold jewelry, which is why imitation alloys are in great demand in the world.An example can also be a gilded piece of jewelry, which is very similar in appearance to the real thing. Also in high demand is medical alloy, which is very similar to gold, but is not made from it. It contains chromium, magnesium, nickel.

When creating gold alloys, much attention is paid to increasing the strength of the final metal, as well as reducing its melting temperature. After a special temperature treatment of the alloy, it must be reheated. Alloys are made in a special production facility under the strict supervision of specialists at every stage.

Marking is placed as follows:

• ЗЛ - gold;
• H - nickel;
• C - zinc;
• PD - palladium;
• PL - platinum;
• KD - cadmium;
• СР - silver;
• C - lead;
• M - copper.

The sample is the quantitative content of gold in a particular alloy. The following gold samples are known in accordance with state standards.

• 375. Includes 5 metals. Most often, copper is used in this alloy, but this does not mean that the jewelry will be completely copper, because it will contain about 40% gold.
• 500. Most often, silver or copper are used as additional components.
• 585. 9 metals are mixed here. Gold of this sample is most actively used in jewelry production.
• 750. 10 elements. Gold in such a ligature is 75%, the metal lends itself to polishing, and therefore shines for a long time.
• 958. This alloy contains about 96% pure gold, but it is rarely used due to its fragility and softness.
• 999. Includes only one metal. Can be used to craft the purest gold bars.

There is also a carat system for gold only. It is used in the USA and European countries. According to her, 24 carats correspond to pure 100% gold.

Gold items are always stamped with a fineness. For branding in different countries of the world, their own inscriptions and drawings are used. The stigma of Russian manufacturers looks like this: a lady in a kokoshnik looking to the right, and next to her are the numbers of the sample, which corresponds to the metal. The hallmark is put by the state assay supervision inspectorate.

For more information on gold sampling, see the video below.