All about 375 gold fineness

The unique status of gold among other metals is due to its external beauty, rarity and physical properties. The constantly growing price for it makes it possible to increase capital. Gold items are not essential goods, but they are always in demand. Few gift can be better than an exclusive piece of jewelry, which speaks of the demand for this synonym for luxury life, wealth and power. Gold items are marked in different ways, the article will talk about gold 375 assay value.

Pure gold cannot fall into our hands. Natural metal is so ductile that it is molded like plasticine. To give greater strength, jewelers use precious metal alloys with other non-ferrous, but non-noble ones, which are called ligatures. These impurities improve the properties of the precious metal, giving the products, in addition to strength, wear resistance, resistance to deformation damage and ease of processing.

A test is put on all the jewelry presented in the windows of boutiques, which by three-digit numbers shows the percentage purity of the composition, or, in other words, the amount of gold in a kilogram of the mixed alloy. It serves as a guarantee that it is not a fake.

In the Russian jewelry industry, gold items are marked with five samples: 375, 500, 585, 750, 958.

Sample 375 has a composition with a small part of gold - only 37.5%, that is, for 1000 parts of the alloy there are 375 parts of pure gold, which corresponds to 9 carats.Such compositions have a drawback - due to the formation of silver sulfide (Ag2S), they darken in air.

For its natural bright yellow color the word Aurum, denoting the chemical element gold in the periodic table, is translated from Latin as "shining dawn" or "light of sunrise". The Russian version of the word is actually a modified form of the adjective "yellow".

The additives contained change the parameters and characteristics of the precious metal. Already the ancient masters noticed that the best ligature is silver and copper.

Depends on the amount of silver and the speed of processing the alloy, and the ductilityas well as a shade that lightens at> 65%, becoming almost white. And with a smaller amount - from 30% to 65% - it gives a rich yellow tint.

Copper reduces the resistance of gold to oxidation, but makes it hard, occupying most of this low-grade alloy. The deep red color of gold in the alloy is given by 60% copper with 2.5% silver. Copper, and most often its alloys with zinc (tompak) and brass, are the most commonly used alloy composition in the jewelry industry.

When creating jewelry 375 samples, the masters use 4 more options for impurities:

• for the shade to be red, a ligature of 52.5% copper and 10% silver is suitable;
• 46% copper and 16.5% silver will give a dark yellow tint;
• the same amount of components - 31% each - guarantees a yellow-pink color;
• in alloys with a predominance of silver up to 65% - the color is white.

It is possible to add a small part to the composition of 375 samples palladium - 3.8%. Then silver and copper will be 10.0% and 48.7%, respectively.

Copper, of course, provides increased strength, but all these ratios of additives do not save jewelry from oxidation under the influence of oxygen contained in the air, and within a short period the product darkens noticeably.

Currently, to change properties and color, a ligature is added palladium, nickel, steel, cadmium, platinum, osmium and rhodium. Due to this, jewelry counters are replenished with new shades of precious metal products. Color spectrum this precious metal in modern production is unusually diverse.

In trend - design with a combination of different tones of consumer gold, for example, combinations of classic yellow with white and red. Jewelry with trendy fantasy shades came to the fore: for example, aquamarine or green.

The market for precious jewelry today offers a huge selection of jewelry for every taste - from budget options to unique pieces of jewelry art. With such a huge assortment, it is not at all easy to understand the consumer properties of the presented products in order to make the right choice.

The main difference, of course, is in the proportion of precious metal in the alloy, which gives beauty to the thing. There is little gold in the 375 assay value, therefore, in terms of aesthetic components, it has low quality indicators.

Sample 585 appeared on the Russian jewelry market relatively recently. The proportion of gold in the alloy is higher, which means that it is of higher quality in terms of aesthetic characteristics.

The purchase of jewelry marked with the sample 375 mark in most cases is based on affordability compared to higher samples. But there are also considerable advantages:

• high wear resistance;
• strength;
• resistance to mechanical stress.

But there is also significant disadvantage... Due to the high amount of copper, the metal's ability to oxidize increases, products are prone to tarnishing, so jewelry made from it often loses its attractiveness during operation.

Due to the large amount of additives, this low-grade composition is sometimes jokingly called by jewelry industry workers gold-bearing copper alloy, although, in reality, by its status it is undoubtedly gold.

Today jewelers in the production of modern low-standard jewelry add special elements to the metal, including rhodium, which significantly increase their resistance to oxidation and are more in the form of a noble metal. As a result, modern 375-grade precious metal is able to retain its presentable appearance, brilliance and beauty longer.

Due to its characteristics - strength, ductility, easy soldering, resistance to scratches - a cheap gold alloy is used in the manufacture of everyday jewelry, for example:

• eyeglass frames;
• framing semi-precious and decorative stones;
• wedding rings that are worn without removing;
• earrings with cubic zirconia, amber, amethyst;
• smoking accessories;
• watch cases and bracelets that need a certain strength;
• decor elements for decorating picture frames, furniture and much more.

The product should not be taken care of from time to time, but regularly. A significant disadvantage of a low sample is its increased activity and susceptibility in an aggressive environment.... The appearance and consumer properties of this alloy are quickly influenced by the oxygen contained in the atmosphere, which promotes the oxidation of the master alloy. This negative effect can be reduced by periodical cleansing and adherence to proper storage conditions.

Preparations with iodine, creams containing compounds of mercury, corrosive liquids, acetone and chlorine are dangerous for a low-grade product.

Deterioration of the surface appearance is prevented by proper care. Dirty deposits are cleaned with an aqueous solution containing several drops of ammonia... Perfectly eats away dirt washing powder diluted in warm water. Dissolved cooking will help salt. Only soap is not suitable for this purpose at all - it will leave a layer of oily film on the decoration.

It is possible to refine and clean darkened and tarnished gold items not only with purchased means, but also with improvised means at home.

A breathtaking shine will return to the jewelry if you polish it with a soft eraser or velor cloth. Old plaque will disappear after mechanical cleaning with a toothbrush with chalk... But you should remember about the measure and do not overdo it with mechanical cleaning, so as not to damage the applied drawing or engraving, which can be erased.

Will come to the rescue and onion juice... He will also polish his favorite piece of jewelry.

To prevent the products from darkening, you should carefully keep them away from sunlight and radiators... Metal is very sensitive to high humidity; jewelry should be wiped dry when it gets wet. It is very important to avoid contact with each other of metal products with different strengths, since ductile gold is too sensitive to contact.

Proper care can keep the jewelry in perfect condition for a long time, so that it can be passed on to the next generation of owners as a heirloom worthy of rave glances.

The oldest decorative gold of the Stone Age was found by archaeologists during excavations on the territory of modern Bulgaria. The circulation of gold around the world in the form of coins began after the Persian conquest of the Lydian kingdom. The most popular gold coin in the world since 1284 and for over 500 years has been the Venetian ducat.

The influence of this metal on the financial sector is difficult to overestimate. People have always used it as currency.

During the "gold rush" in America was the first recorded 17-pound nugget found in North Carolina. But, of course, it cannot be compared with the heaviest mined ingot, weighing 250 kilograms.

Despite the extracted by mankind in all centuries from 150 to 200 thousand tons of rare metal, it is believed that this is only an insignificant part of it, no more than 1%, and the rest of the gold reserves are in the magma of our planet. AND a huge amount is found in the waters of the oceans, but scientists have not yet invented technologies for extracting it from the ocean depths.

This precious metal is found not only on planet Earth. At the end of the 20th century, it became known that there is plenty of it in space. Only on the asteroid Eros there is more of it than it has been mined for all centuries on earth. And scientists are struggling to solve technologies for extracting gold from space.

The list of beneficial properties of gold has grown significantly in recent years. Scientists constantly carry out numerous experiments with gold and find more and more applications for it. Today gold is used not only as jewelry. It is widely used in the implementation of modern technologies in various industries; its practical use has also been found in medicine.

The use of gold in aviation and the space industry is increasing. The use of gold in the modern world is increasingly found in:

• telecommunications;
• nanotechnology;
• space industry.

One of the discoveries made by American scientists in the 21st century is the ability of a given metal to change its molecular structure under the influence of an electric field. And after the end of the impact - to restore it yourself.

Under the influence of an electric field, the yellow metal is able to convert carbon monoxide into carbon dioxide, and act both as a conductor and as a current insulator. It has also been experimentally proven that it can exhibit magnetic properties. These properties are very important in the electronics industry.

It can even be eaten, but only in small quantities in the form of metal flakes or plates along with food or drinks. If the portions are small, then the process of taking this kind of food will not bring any harm, because the human body already contains about 10 mg of gold. About half of this amount is concentrated in the bones, its content in the blood is about 1 mg per liter, small amounts can be found in hair, skin and nails.

Goldschlager - Swiss schnapps worth $ 300 per bottle. This most amazing alcoholic beverage in the world contains real gold in flakes - approximately 13 mg per liter.

Modern Korean cosmetology effectively uses biogold in compounds with amino acids, natural herbal ingredients and extracts. Colloidal gold is an excellent catalyst that accelerates all the beneficial changes that occur in the skin during cosmetic procedures.

The metal popular all over the world is stretched in thread-threads for finishing and decorating expensive costumes... Of course, such threads are very expensive and are produced in very small quantities for decorative purposes.

Perhaps, it will soon become impossible to call the noble metal, beloved all over the world, yellow. After all, science and technology do not stand still.Various desired shades, far from the traditional and familiar yellow color, will be achieved not by changing the composition of the ligature, but by applying innovative technologies.

Scientists from Great Britain have learned to change the yellow metal in all colors of the rainbow. They have invented advanced technologies that can change the frequencies of electrons, making them reflect light in the right way, and thereby give the metal the desired hue.

For information on how to test gold for samples, see the next video.