Gold was the first noble metal that man discovered, and today it is used in many fields. In the jewelry industry, gold has been most successful. There is a gradation of value of the metal. Every woman receiving a jewelry gift from a man, be sure to pay attention to the carat or proof. This indicator informs about the amount of pure precious metalThe quality of the alloy used to make the jewelry. So how do we learn to judge alloy purity and quality by the hallmark on a piece?
The meaning and origin of the word "carat". Composition of gold in bullion and consumer goods
The word carat in Latin sounds like "fruit of the carob tree. Its origin is in the Eastern countries. The value of the plant is represented by its seeds, which were the prototypical unit for measuring the purity of gold. Earlier they were used to measure the weight of expensive stones.
This method of evaluation was not the most reliable, so traders from different countries decided to equate 1 carat to 205 mlg. Later the established weight was reduced to 200 mlg for convenience. And today this measuring system remains the only one for the evaluation of precious stones all over the world.
Over time, traders began to value valuable seeds not only stones. Gold carat made it possible to determine the quality of rings, earrings, bracelets and other jewelry. The maximum gold content according to the grading system was 24 carats.
That is how much is indicated on bank bullion. However, pure gold is very soft and unsuitable for making various items. That's why they add impurities to improve its qualities for use. This is where the carat ratio, which shows the optimal ratio of gold to gold content, becomes important. ligatures.
Systems for assessing gold purity
In the history of the jewelry industry, there were four systems of assessing the purity of the gold alloy: lot, spool, metric, carat. Today, however, only the last two are relevant, by means of which the amount of precious metal can be measured.
Metric system and samples
Russia and some post-Soviet states use the metric system for assessing the purity of the metal. According to it, the assay shows the amount of pure gold in 1,000 fractions of the alloy. In other words, how many milligrams of gold contain 1 gram of the alloy.
The following admissible values are approved: 375, 500, 585, 750, 900, 916, 958, 999. However, the range is not limited to these samples, they are only frequently used.
Carat system. The meaning of caratality
This system includes the following values: 9, 12, 14, 18, 22, 23, 24. Pure gold is considered to be 24-carat gold that contains a minimum of impurities. Carat of gold shows the amount of pure metal in the alloy relative to 24 carats. The system is used by the world's jewelry specialists to determine the proportion of pure metal in products.
In the U.S. and Europe it is only used to measure the purity of gold alloys, it is not applicable to other metals.
Zolotnik system of tsarist Russia
For more than two centuries Russia used the ash system of measurement to assess the purity of precious metals. It was used to evaluate silver and gold, comparing them to the number of gold pieces. It was not until 1927 that it was replaced by metric measurement.
The spool unit, like the metric unit, helps determine the ratio of pure precious metal to ligature. It is based on 96 units - spollets. 999 precious metal corresponds to 96 spools.
To convert the sprockets to a familiar value, divide the sprockets by 96 and multiply by 1000.
Carat and grade of reference gold on the world market
The carat value of jewelry is used by America, Great Britain, Switzerland and other European countries.
The standard of gold on the world market is considered to be 24 carats. Every day the price of gold is determined on the precious metals exchange exactly in relation to bank bullion bars, consisting of 99.99 % of the precious metal. The assay of such gold stocks is 999.
Using a simple example of ligature calculation, it is possible to understand how the correlation Sample and carats. To know how much of the alloy contains ligature, you need to subtract the number of carats on the hallmark from 24k. A 12-carat piece of jewelry uses 12k of other metals. This simple translation allows you to equate the carats to the metric number, in which 1000 grams (24k) consists of 500 gram of gold (12k) and 500 grams of ligature (12k). Accordingly, 12k = a sample of 500.
The formula for translating carats into a sample
Bank bullion at 99.9% consists of pure precious metal. In Russia, the metric system with a marking in the form of a proof is officially accepted for jewelry evaluation. Any figure from other measurement systems can be easily converted to a fraction of the precious metal used.
To determine which metal sample corresponds to the specified number of carats on the piece, you can use a simple formula:
carats / 24 * 1000
The resulting figure will appear in the row of values of the metric system.
Table: Ratio of different evaluation systems
Where to find the stamp, sample and manufacturer's mark on the product
Every ring, bracelet, chain, and other jewelry necessarily meets the hallmark of one of the existing systems of evaluation. Any jewelry shop can only sell jewelry that has a state assay mark. The imprint is called a nameplate, and is identified by numbers and letters. The figures indicate the year of manufacture and proof. The alphabetic symbol identifies the manufacturer.
Any piece of jewelry is sold with a label and details: name of the manufacturer, name of the jewelry, code, article number, weight. In addition, the size of the item and the name of inserts, if any, are indicated. According to GOST, the label is attached to the items with a white thread and a seal.
Only the Assay Chamber of the Ministry of Finance of the Russian Federation regulates and carries out the marking of the product. The state marking can be lasered or minted. The presence of such a mark indicates the authenticity of the jewelry and the passing of the appropriate checks.
This includes the stamp, the certificate mark, which are applied by the same or different images. The sign of the certificate may be an image of a star with a hammer and sickle, which is characteristic of Soviet goldor the head of a woman in a kokoshnik turned to the right.
The branding of any piece is applied directly to the alloy. Focusing on the type of jewelry, the branding is put inside, on clasps, other connecting elements, hidden from sight.
Why it's better to trust the test on the product
Each jewel of domestic or imported origin must have the necessary markings. Imported gold jewelry is always marked with carats and the word "gold". Certificates for trade are compulsory.
It is important to read the name plate correctly, especially on jewelry imported from other countries. The majority of such jewelry is gilded costume jewellery or silver, which is also proved by the presence of the corresponding markings. At the same time the price of this jewelry may correspond to the original.
Any gold jewel brought for sale in the Russian Federation requires an assay. Then the assay is indicated along with the carats.
Determination of the carateness of the product by the acid method. Instructions
Using simple methods, it is possible to install gold authenticity. But how do you determine the grade or carat? This is difficult to do at home, because you have to buy special reagents. The jeweler can use the acid method to determine the purity of jewelry. It is also used in pawnshop, buying up precious objects. In this case, a small scratch is made on the piece of jewelry and a drop of acid is placed on it, which reacts with the precious metal. The result is used to determine how many carats the item is worth.
Step-by-step execution of the test:
- Clean the product of dirt, make a small scratch.
- Take reagents designed for different carats. First drop from the vial with the lowest carat value on the scratch. If the carat is higher than the one indicated on the vial, the color of the alloy will not change. Then the experiment should be repeated until a match is found.
- When the carat of the reagent matches the noble metal, the place of damage will not significantly change its hue. If the grade of the jewelry differs by several carats, the scratch will be covered by a slight rust. If the alloy is several carats higher than the one indicated on the vial, the scratch will dissolve and disappear.
Set of reagents to test the caratality of gold. Average price on the Internet
Use a chemical method of testing you can also buy a set of chemicals at home. On average, the cost of a vial with a reagent will cost 15 rubles. A complete set can be purchased for 200-250 rubles.
To perform the experiment at home, you must first carefully study the instructions. The accuracy of the result depends on the correct use of the reagents. Safety precautions in the use of acids must also not be forgotten.
To determine the purity of the metal, you can use salts, a solution of gold chloride. After applying the appropriate reagent to the jewelry, a spot appears, the color of which can be used to determine which grade it belongs to:
- 750-958: Various brown shades are formed;
- 583-585: a light brown stain will remain;
- White alloy 583-585: orange-golden tone appears;
- 375: A greenish stain will remain.
There are a lot of tips on the Internet on how to check gold. And how do you determine the proof or carats of gold?
How do I convert carats to proofs when buying jewelry abroad?
How many carats correspond to pure gold?
How much is a carat of gold in grams?
If we talk about precious metals carat shows the ratio of pure gold and alloys in the alloys for the manufacture of jewelry, respectively, will always be different.
Pure gold is how many carats?
Video: determining the caratage of gold jewelry
It is important to understand that not all countries require branding and the presence of the name plate. This means that the authenticity of not all imported products can be easily established upon superficial inspection.