Good day! Those who bought jewelry abroad often do not understand what 18 carat gold means: what grade is it and how much precious metal is contained in such an alloy? People from the territory of the former USSR are little familiar with the carat testing system - we have been using the metric system for a long time. The situation is aggravated by the existence of the “diamond carat,” which measures the weight of precious stones. But gold items purchased abroad are often marked with karat marks.
What is carat
The karat system involves designating the percentage of gold in the alloy with numbers from 9 to 24, where 24 is the highest standard, that is, 100%. Physically, the absolute purity of the metal is unattainable and impurities are present in trace amounts, therefore the “thousandth” sample is designated by the number 999 - 99.9%.
I’ll answer the main question right away: in Russia, jewelry with a hallmark of 18K is indicated by the 750 mark. They contain 75% pure gold.
Origin of the word
The breadfruit tree of John, known to people since biblical times, grows in the Mediterranean - Ceratonia capita. Its fruits are consumed as a delicacy, added to immunostimulating complexes, and compote is made from them. But ceratonia also has a non-standard property for plants: it produces seeds, the mass of which is constant and equal to ~0.19 g. Our ancient ancestors noticed this and began to use a measure of weight that refers to the seed of ceratonia (Greek cerátiοn), the carat.
The modern carat (measure of weight) has not changed since then and is 0.2 g.
How to determine carat content
You won’t be able to measure the gold content in jewelry if the sample has worn off and is hard to see at home. The maximum that will be possible is to distinguish a gold alloy from an obvious fake. But if the ring has another standard - metric or spool (it is found on jewelry and luxury items produced before the revolution or immediately after), then you can convert its value into the carat system.
How to convert to the metric system and sample correspondence table
There are two ways to convert carats to thousandths of mass.
- Calculate. A complex, but universal method that works with unpopular samples. We take 24 carats as 100% and get a carat equal to 4.17% of the total mass. If a product is marked 18K, then in the metric system it is 4.17 x 18 = 75%, that is, 750 fine.
- Use the correspondence table. I'm including a spool test in case you come across an antique tiara.
| Metric system | 999 | 958 | 900 | 750 | 585 | 500 | 375 |
| Carat system | 24 | 23 | 22 | 18 | 14 | 12 | 9 |
| Spool system | 96 | 92 | 88 | 72 | 56 | 48 | 36 |
| Gold content | 99,9 % | 95,8 % | 90 % | 75 % | 58,5 % | 50 % | 37,5 % |
Legislative regulation
In Russia, all precious metal products with a purity of at least 300 are subject to hallmarking and hallmarking (actually 375, because we do not produce lower-grade gold). The metric value of the sample is applied to the jewelry; it is up to the buyer to convert it into carats.
Metric system
More understandable for us, since the numerical designation is the quantitative gold content per 1000 units of the alloy. For example, in one kilogram there is 750 fineness - 750 grams of pure precious metal. This system is used by the State Assay Chamber of the Russian Federation, therefore jewelry is stamped 375, 585, 750, which is a guarantee of its quality.
Imported jewelry, if sold legally in stores, with the designation 14 K, 18 K and others, must be checked by the government service. In addition to the carats, they should have an imprint of 585 or 750 with a woman in a kokoshnik.
Counterfeiting a stamp is a criminal offense, however, when purchasing products abroad, you need to take into account the high probability of fraud. The inscription 14 K or 18 K is very easy to put on jewelry made of any metal. Quite often they can be found on gold-plated products, which they try to sell as full-fledged gold, although their cost is very much lower.
- This is useful to know: How much does 583 Soviet gold cost now?
A little about this test
750 standard is popular among jewelers and their clients. This is the most successful combination of the purity of a noble metal and ease of use: 999 standard is too soft to be worn constantly. However, a gold content of 75% is sufficient for the product to retain the inherent luster of pure gold.
Composition and properties
As can be understood from the name of the sample, 25% of the mass of our pendant or chain is made up of ligature (foreign metals). Impurities are added to gold primarily because the pure precious metal is extremely sensitive to damage. The 999.9 fine bank bullion can be scratched with a fingernail. This is unacceptable for jewelry that we wear on our bodies, so a ligature is added to gold to increase its wear resistance.
750 gold is common and contains the following additives in different proportions:
- copper (the main alloying component of most alloys);
- silver (also present almost everywhere);
- palladium (added to white gold);
- platinum (rare);
- nickel (rare).
Strength
The price to pay for the prestige of a high-grade alloy and its characteristic shine is the need to wear it carefully. 18K jewelry is easier to break than low-grade analogues.
Alloy shade chart
To understand what shade the alloy will give to gold, you need to look at the original color of the alloying metal. Often there are several additives. Let's look at the popular options for metal “cocktails”:
| Try | Color | Gold | Silver | Copper | Palladium |
| 18 carat | red | 75 % | 40 % | 21 % | No |
| 18 carat | pink | 75 % | 12,5 % | 12,5 % | No |
| 18 carat | yellow | 75 % | 17 % | 8 % | No |
| 18 carat | greenish | 75 % | 25 % | No | No |
| 18 carat | white | 75 % | 5 % | No | 20 % |
Brand
In addition to the hallmark, each piece of jewelry must have an imprint of the name of the manufacturer. The name plate is registered by a branch of the Assay Chamber under the Ministry of Finance of the Russian Federation and contains encrypted information about the year of manufacture of the jewelry and the factory.
The 18-carat ring produced by the Russian factory will be marked 750.
Carat system
To improve strength and other characteristics, and also, importantly, reduce costs, cheaper metals such as copper and silver began to be added to pure gold since ancient times. The more such impurities, the lower the sample.
- This is interesting: Platinum or gold – which is more expensive?
In the modern world, there are two systems for assessing the quality of gold - metric and carat. In carat, the highest standard 999.9 corresponds to 24 K. There are also the most common values 8 K, 10 K, 14 K, 18 K. We will consider the recalculation of karats using the example of 18 K gold that interests us.
18 : 24 = 0,750
We get a simple and unambiguous answer: 18 carats is 750 gold.
Using this formula, it is easy to find out any other ratio by substituting the required value instead of 18.
Carats are widely used in the West, however, they can be considered a relic of the past; the whole world is slowly but surely moving towards a metric quality assessment system. Increasingly, next to the 18 K print, the numbers 0.750 are found.
Difference between 14 and 18 carats
18K is considered an elite grade. 14K (585 standard) is worn mainly as an everyday option, saving the expensive 750 standard for special occasions.
Cleanliness, hardness and durability
The more alloys in the alloy, the more pronounced the properties of the alloying components. 585 sample, consisting of almost half of impurities, is much lighter, harder and stronger than 750 sample, and is less susceptible to minor damage such as scratches or dents.
Color
The color of pure gold is bright yellow. An alloy containing a lot of copper takes on a reddish tint (pure copper has a rich brick-pink color). Green gold is coming into fashion, which contains no copper at all, but a lot of silver.
Many jewelers use the rhodium plating technique in their work - coating products with a thin (1.5–25 microns) layer of rhodium (a rare platinum group metal, many times harder than gold). Rhodium-plated jewelry can be not only the classic yellow, pink and white colors, but also black.
Markings
¾ gold items are marked o (units of measurement are indicated after the numbers). In Europe, such a ring will most likely have two marks at once: carat and metric (750).
Price
In Arab countries, you can find jewelry positioned by sellers as almost pure gold, but the reliability of these assurances is questionable.
Expert opinion
Vsevolod Kozlovsky
6 years in jewelry making. Knows everything about samples and can identify a fake in 12 seconds
Therefore, 750 is the highest of jewelry standards, given that 958 turned out to be unsuccessful in terms of price and quality. It is also the most expensive: in Russian stores such jewelry costs on average 1.13 times more than standard 14-karat jewelry. If you go to pawn shops and try to sell such metal as scrap, it will be valued at 1.25 times higher than 14-karat.
750 gold
The most common standard is 585 gold – this is the result of a long search for the best ratio of quality characteristics and cost. Such jewelry is the most popular and is in the budget segment of the market. For the production of luxury products with precious stones, 750 standard is used, which is much more expensive.
Red jewelry is quite rare; the vast majority have a yellow tint, closer to pure metal. A special place is occupied by noble white gold, obtained by adding platinum or palladium; it is almost always used for the production of diamond jewelry.
What to consider when purchasing products
In order for the jewelry to please you for a long time, do not make emotional purchases. Consider where you plan to wear your new item. 18-karat gold is suitable for festive outfits and for everyday wear, if it is gentle.
How to distinguish gold from gilding
- Pay attention to the brand. There are no hallmarks that indicate gold plating, and a silver ring that is plated with gold will be marked as sterling silver (875 or 925 fineness).
- Try scratching the item with a thin needle. If there is base metal underneath the gold plating, the scratch will be darker than the surface.
- Stores sometimes have assay needle sets available - you can ask the seller to make sure that the gold is real, or contact a pawnshop with this request.
- You can understand that the jewelry is fake without checking it. If you have worn it for several days or weeks and it has darkened, it is definitely not gold.
Below watch a visual video on how to distinguish a fake:
Why high purity is not always good
A high standard imposes restrictions on the wearer. It is better to go for things with a carat content below 18 if you:
- you buy jewelry that you want to always wear (for example, to decorate your neck on a mountain hike);
- you are choosing a gift for a child who, due to his age, will not be able to handle it carefully.
Why are low carats bad?
Low-grade gold is inferior in beauty to high-grade gold. It shines duller and looks cheaper. This is not so noticeable when you are wearing one piece of jewelry, but a set of several pieces of different grades will look uneven and give off a low-carat element.
Nickel allergy
Sometimes (infrequently) nickel is present in multicomponent jewelry alloys. Gold items (especially high-ligature ones) can become an allergen if they contain nickel.
The only way out of the situation is not to wear alloys containing nickel. Humanity has not yet learned to cure allergies. Medicine either uses drugs to suppress symptoms or recommends avoiding the allergen. If your body recognizes nickel as a danger, you should take a closer look at jewelry without it.
