Noble metal in its pure form cannot be used either to create objects of beauty or for industrial needs. High purity gold is overly elastic and brittle. Alloy additives are needed to give the metal hardness and the necessary ductility.
750 gold is considered ideal.
Measuring the purity of a precious metal
Gold hallmark - what is it? Breakdown is a system for measuring the volume of pure metal. It can be metric, carat, lot or spool. The metric standard determines the volume of pure gold in a thousand parts of the alloy and is marked with the corresponding numbers: 375, 500, 583, 750, 950, 999. In gold of the 750th standard, the noble metal makes up three quarters, the rest comes from various alloy additives.
In Western countries, the amount of pure gold in an item is measured in carats. The basis is not 1000, but 24 parts of the alloy. Labeling also depends on the percentage.
How do the metric and carat systems compare?
| Carat | Metric | Precious metal content (percentage) |
| 24 | 999 | 99,9 |
| 23 | 958 | 95,8 |
| 18 | 750 | 75 |
| 14 | 585 | 58,5 |
| 14 | 583 | 58,3 |
| 12 | 500 | 50 |
| 9 | 375 | 37,5 |
Thus, 18 karat gold is similar to 750 gold.
Authenticity of the mark
Of course, you should pay attention not only to the digital designation when purchasing a product, but also to the shape. Each country of origin has its own stamp forms. On Russian objects, the symbols are made in the form of a female profile or in the form of a hammer and sickle on a five-pointed star. How to check whether your product has a genuine mark and hallmark or not. To do this, you need to clean the surface of the jewelry and apply it in a special way so that strips of metal remain on it. After that, chemical reagents are applied to them one by one, each of which is intended for a specific type of alloy. Today on the Russian market there are reagents for all possible alloys. If the content of the metal in question in the alloy is as specified, the color of the yellow streaks will not change and they will not disappear. If the gold stripes completely disappear, this indicates that there is no metal in the product at all.
Benefits of 750 sample
Craftsmen all over the world prefer 750-carat metal and call it the gold standard for jewelry. Compared to other alloys, it is better processed, which allows you to create chains, bracelets, rings and earrings from gold of incredible beauty.
In addition, jewelry connoisseurs of 750 gold are attracted by the high percentage of pure element.
What other advantages does this gold alloy have:
- it is most resistant to any type of corrosion and aggressive environments;
- has excellent malleability and fluidity;
- able to retain color and shine for a long time;
- Suitable for the manufacture of complex jewelry and technical designs.
How much does 750 gold cost? Due to its high purity, it is not very cheap. The price depends on the composition of the ligature and on market quotes. In 2021, it averaged 1,700 rubles per gram. Of course, jewelry is more expensive, because the work of the craftsman, the cost of inlay and the markup on sale are also assessed here. Additionally, a high density index affects the weight, and its price also depends on the weight of the jewelry.
Cleaning 750 gold items
In order for products marked 750 to serve for a long time and please with their appearance, they must be properly cared for. Be sure to store your jewelry in a special box or case. It is advisable to wipe and polish the product with a suede cloth every day. You can also use flannel.
The biggest enemy is chlorine. Therefore, it is better to remove jewelry before cleaning the house or visiting the pool. Sweat can also damage your appearance, so before going to the gym you should put your jewelry in a case. Also, do not forget about the adverse effects of mercury on the product.
Even some cosmetics can affect decoration. Therefore, you should avoid touching the product.
Another hostile environment is iodine solution. You can remove iodine stains with hyposulfite. The decoration is immersed in the solution for 20 minutes, after which it is washed and rubbed with a cloth.
Goya paste will help you give your decoration its former shine. Apply a small amount to a woolen cloth and wipe the product thoroughly. Onion juice may also help. Place the jewelry in it for 2 hours, then rinse and polish with a soft cloth.
Sometimes dark spots appear on jewelry. A solution of soap and ammonia will help remove them. The product should be kept in the solution for about 15 minutes, and then rinsed and dried. All these methods can help you keep your jewelry in excellent condition for many years.
Effect of ligature additives
The ligature options for 750 gold are varied. This could be copper, silver, nickel, zinc, even precious palladium and platinum. Each component brings unique qualities to the composition.
To give strength, copper and silver are added to the alloy. If the product is decorated with colored enamel, the copper content should not exceed 16 percent.
This additive can make the enamel dull. Also, gold with a large amount of copper can darken slightly over time.
Not only the quality, but also the color of the alloy depends on the alloy:
| Hue | Ligature volume (in percent) | ||
| Copper | Silver | Palladium | |
| Light yellow | 10 | 15 | 0 |
| Bright yellow | 12,5 | 12,5 | 0 |
| Green | 0 | 25 | 0 |
| Pale green | 6,3 | 18,7 | 0 |
| Pinkish | 16,7 | 8,3 | 0 |
| Red | 21 | 4 | 0 |
| White | 0 | 5 | 20 |
To create the desired shade, jewelers adjust the amount of one or another additive. White 18k gold items will acquire a bluish shine if they are plated with rhodium. The decoration becomes stronger, but the coating will have to be renewed periodically.
Palladium, zinc, nickel and platinum give the now fashionable white shade. The first and last components are very expensive, but such alloys are still cheaper than pure platinum, and are in no way inferior in quality. The white tone perfectly emphasizes the beauty of diamonds; such jewelry becomes real works of art.
Uses of gold
According to historical information, gold is the pioneer metal with which humanity interacted. Acquaintance with him took place 2-3 thousand years ago, as evidenced by the jewelry found at the excavations. There are also references to this precious metal in the Iliad and the Bible. Gold also aroused great curiosity among alchemists, who often sought ways to transform metals into precious metals, which were credited with great power.
In the modern world, gold has several functions:
- in commodity production it performs the function of money;
- in art it is used for jewelry work;
- in medicine it is used as components of some drugs;
- also used in the chemical industry and electrical equipment.
Use of noble material
750 gold standard makes it possible to use the precious metal in measuring instruments, medical equipment and electronics. It is used to produce ingots for storage in jars, decorative wire and plates for lining various surfaces. But it is most widely used in the creation of jewelry masterpieces.
Complex work, for example, making designer jewelry from precious wire or a relief punch with strong pressure on the surface, can only be done from 750 gold.
The density of the composition encourages creative experiments: luxury decor items are made from such a noble metal.
To improve performance characteristics, alloys are produced using the “metal steaming” method. Thanks to this technology, strength and hardness are achieved. For a softer structure, additional processing is required.
World-famous designers (for example, Gucci, Armani) create stunning collections from soft Italian gold. It can be pinkish, white or yellow, which is used by craftsmen to play on contrasts.
Marking. Image of the Russian mark
In Russia, 750 gold is assayed in a certain way. This makes it possible to distinguish it from platinum group metals, silver, and other precious metals. In simple words, a stamp is a sign of quality that confirms the gold content in a certain amount. On the products you can find a name tag - the manufacturer's trademark.
Marking, branding and assaying of jewelry
The presence of a state hallmark is mandatory; it contains information:
- hallmark(gold 750);
- hallmark;
- code of the State Assay Supervision Inspectorate (M).
"Industrial" metal
Looking deeper into the history of Russia, you can find mention of silver 72, from which 5-, 10-, 15- and 20-kopeck coins were minted until 1867. Converting this indicator from the spool testing system to the currently existing metric system, we get the same 750 sample.
The mentioned spool (Russian) system was officially used in Russia from 1711 to 1927. When using it, the amount of noble metal contained in 96 spools was taken into account. Then a transition was made to the metric system, which is based on the ratio of the main and alloying components in a thousand parts of the master alloy. This testing procedure is still used by most countries. To switch from a spool test to a metric one, it is enough to divide the value of the first by 96 and multiply by 1000.
Currently, in accordance with current legislation, the jewelry industry of the Russian Federation uses 960-, 925-, 875-, 830- and 800-grade silver alloys. Compounds with a lower content of the noble component, as in Soviet times, are successfully used in industrial production. Alloy Ag 720-750 is used for the manufacture of needles, springs and other similar products operating under high loads.
Silver solders, which contain copper and zinc as alloying components, have proven themselves to be excellent. Immunity to oxidation has led to the successful use of 750 silver in the aviation and space industries, and due to its high electrical conductivity, such compounds have retained their position in electrical engineering. In denture production, a combination of argentum (75 percent) and palladium is successfully used.
Statistics show that if in the 30s of the last century a quarter of the silver produced in the world was used for technical needs, now more than 70 percent of the noble metal is used for these purposes.
From the above, we can conclude that an alloy containing 750 parts of silver and 250 alloying components cannot legally be used for the manufacture of jewelry and household items. But its importance as an “industrial” metal is constantly increasing.
Products and decorations
Items with higher markings belong to the premium class; no one wears them in everyday hustle and bustle. These jewelry items are for special occasions. Plasticity allows you to create complex carved elements and openwork patterns. The beauty of an object depends on the skill of the jeweler.
High grade noble metal is not involved in mass production. It is mainly used to create one-off, exclusive products with precious stone inserts.
Impurities in certain quantities expand the range of shades of the sample. In the traditional version, the raw material is yellow and is used to make wedding rings, earrings, and chains. Nickel and palladium as alloys color the alloy white. This material is valued for setting diamonds. The cost of the resulting products is incredibly high, especially if platinum is present in the gold alloy.
