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What a measure of one carat. History of weight measurement. The biggest diamond

In any area of ​​trade, a standard is needed - a benchmark that will universal way assessing the value of something. This is a certain measure of weight or volume, as well as a quality standard. In the jewelry industry, where metals are sold in small quantities, stones are quite microscopic, even a spray layer of particles is valued noble metal, has always needed its own measure of weight. Karat has firmly entered the lives of people, measuring the mass of gold in grams, or the purity and volume of precious stones. Gold is one of the most sought-after metals, it is used as an indicator of the country's wealth, regulates trading on the stock exchange, is used in industry and gives joy to owners jewelry. Specialists - gold miners, sales intermediaries, stock brokers, jewelers and their assistants - know how to determine the volume of gold, its quality and value using this measure. Just a few tips will help you figure it out and finally find out how many grams are in your gold product, if its sample is indicated in gold karat, where this measurement system came from and how to apply it.

History of karat

The carat is not an element of the system of measures and weights, therefore it is called off-system. The name comes from the carob tree Ceratonia siliqua. This is an evergreen tree that has long been common in the Mediterranean. It produced fruit, pods that always matched one another in weight and volume. Noticing this feature, people began to use its pods as a weight standard since biblical times. During the Roman Empire, mature dry pods were introduced into the system of measures, one unit was equal to 0.19 grams and was called siliqua. Karat is only the Greek version of this name, which came into use later.

There are many varieties of karat that are similar in essence, but have different numerical equivalents. A metric carat is 0.2 grams. In the Middle East and North Africa, kirat was used - the so-called Arabic carat, which was measured in milligrams and had an approximate value (from 195 to 223 mg). An English carat is also an indicator in milligrams, it equals 205 mg. Egypt has always had its own measures for measurements. Their carat is measured in fractions of faddan and kadah, and was approximately 0.064 liters or just over 175 square meters. meters. These measures do not apply to precious metals and stones.

Metal and alloys

A very important parameter of the metal is the purity of gold. To be sure of the quality of the metal, you should consider a special marking on the product. It is this parameter that allows you to determine the degree of purity of the alloy. One carat here is one fraction of a pure substance out of 24 in this particular bar, coin or other product.

There are many alloys of gold, and this is more of a necessity, because gold itself is a very soft metal, it does not hold its shape and is easily deformed. Over many years of development in the jewelry field, traditional alloys have appeared that do not cause allergies in humans, make the metal resistant and hold its shape well, give beautiful shade. Very often silver and copper are used for alloys. For non-ferrous metals - white, green, black, rose gold, additional tint additives are also used. To understand how valuable an item from precious metal, you need to know not only its weight and type of gold, but also the sample, which can be measured in numerical value or carats. A numerical value can more accurately describe the percentage of pure gold (for example, 24 carats equals 999 fineness). In the United States, the gold standard is often indicated in carats, while in Europe, metric markings are preferred.

Weight and numbers

Despite all the intricacies of measurements, I would like to know how many grams of the usual, familiar to our person grams in a gold product. So let's start with the metric carat. It was first used in Spain. This is a weight equal to ⅕ of a gram, or 0.2 grams or 200 mg. Here the tradition of medieval measurements is continued, the difference is only in a more accurate figure of the standard.

Now the British carat system is used to indicate the purity of gold samples. With its help, you can find out the percentage of gold content and the percentage of impurities. The number 24, which is the maximum and corresponds to 100%, is easily divided in half and into other equal shares. So, 12 carats - 50% pure gold, 6 carats - 25%, 18 carats - 75%. For other figures, the percentage of 1 carat will help - 4.2%.

Sample purity

Samples can be converted to the carat system. The purest used in jewelry business sample - 958. It corresponds to 23 carats. Impurities here are necessary to change the properties of the material in the direction of greater strength. 22 carats is 917, which is also fairly clean. 18 carats or 750 assay — traditional look alloy, which allows you to make a balanced alloy with other metals. It is this numerical indicator can be called optimal. 14 carats - 585 gold. It is very common both in Russia and in Europe. Due to a large percentage of impurities, it can get an original shade, and also has sufficient hardness for various jewelry manipulations - twisting, stretching, straightening to the state of a sheet. 10 carats is 416 samples, and just over 40% pure gold. This is the lowest metal purity bar in the US. In Russia, a 375 sample of 9 carats is also acceptable. In the East, 8 carat markings are also used, containing 33.3% gold. To convert gold in carats and convert it to the metric system, the table published below may come in handy:

Ounce

For trading on the stock exchange, a troy ounce is used, which is a fairly accurate measure of measurement. Do not confuse it with the previously described. Troy ounce corresponds only to pure gold, with a purity index of 999 samples. It indicates the weight of the metal, and in accordance with this helps to find out its price in the world market. By weight, it is approximately 31.103 grams. If you purchase investment coins, bullion or a virtual amount of gold through a bank or exchange, you will come across exactly this value, which is denoted as ozt.

What to pay attention to?

Purchasing gold in carats with high rate cleanliness will be the most reasonable investment. If necessary, you can sell a ring or chain for more high price, since the price of gold has not fallen for many years.

On the other hand, for those who value above all the aesthetic component, not intending to invest in jewelry, numerous alloys may be suitable. The use of non-ferrous metal will allow you to create flower or fantasy compositions of unique beauty.

The strength of the alloys will allow you to make the finest cut of the product and decorate it with filigree carvings. A combination of pink or green gold with a similar shade precious stone looks very nice. In any case, when purchasing a thing from a jeweler, find out about the content of precious metals, the quality of stones, the percentage of pure gold that makes up the alloy. So you can be sure that you did not make a mistake with the purchase.

What is a carat? For jewelers, this term has two meanings. One is used to indicate the content of precious metals in an alloy, the other is used as a unit of measurement for the weight of precious stones and pearls.

In Russia and in most European countries, the metric system of measurement (and silver) in the alloy is adopted. It is extremely clear and understandable. In one gram of a 925 sample product there will be 0.925 grams of noble metal and 0.075 grams of base metal impurities. Pure gold and silver will be 999 samples.

In the USA, Canada, Great Britain, in some countries of the Middle East, the carat system for measuring the content of precious metal in an alloy is common. The system is duodecimal. A precious metal of 24 carats is considered absolutely pure. A 22-carat test indicates that the product contains 22 parts of pure gold and 2 parts of impurities. Accordingly, in the decoration, on which there is a test of 10 carats, there will be 10 parts of gold and 14 parts of impurities (ligatures).

In carats

If on precious decoration worth a try:

  • 9 carats - this means that the weight of gold or silver is 0.375 of the weight of the alloy;
  • 12 carats - the weight of the precious metal is 0.500 of the weight of the alloy;
  • 14 carats - the weight of the precious metal is 0.583 of the weight of the alloy;
  • 15 carats - the mass of the precious metal is 0.625 of the mass of the alloy;
  • 18 carats - the weight of the precious metal is 0.750 of the weight of the alloy;
  • 22 carats - weight is 0.916 of the weight of the alloy.

To convert carats to grams, you need to have an existing sample, for example, divide 18 carats by 24 and multiply the result by 1000.

IN different countries jewelry of different carats is popular. In the US, 14 and 10 carat gold is common. In the countries of Southeast Asia, they love high-grade gold - 22 carats. And in Portugal there is a unique sample - 19.2 carats.

Compliance with metric and carat sampling systems

To designate a sample, hallmarks containing the letter “K” after the value of the sample are used:

Marks like "12K", "15K" mean that the product is made of alloys of 500 and 625 tests.

The abbreviation on the hallmark “KGP” (stands for karat gold plated) indicates that the product is gilded. Therefore, if the ring is stamped "18KGP" - this means that the product is not gold, but gilded with 18-carat gold.

How many carats are in diamonds and gems?

IN English language different spelling of words helps not to get confused in carats. To determine the mass of stones, the word carat is used, for gold - karat.

Carat (carat) is a measure that is used to indicate the mass and gems. It is equal to 200 milligrams (0.2 grams).

A sapphire, ruby, and diamond of the same size will have different carats because their density is different. If you put precious stones of the same weight of 1 carat next to each other, then the largest will look like an emerald, followed by a diamond, and the smallest will be a ruby.

A diamond weighing more than one carat is considered large. Its diameter can reach 0.5 cm. Diamonds weighing 5 carats are sold only at auctions. But stones weighing more than 25 carats get their own names.

The larger the gem, the more expensive its price. The largest diamond in the world weighs 545 carats.

Diamonds in carats

mass semi-precious stones also measured in carats. But their weight does not affect the cost so much. Other factors play a role here: brightness of color, shape, cut.

For mass measurement natural pearls use gran. It is equal to a quarter of a carat. But no one measures uncut stones in carats. Their weight is taken into account in grams.

This is interesting

The seeds of the carob tree were called carats in ancient times. They differed little in size, so they were used as a unit of measurement. In the past, different countries had a variety of karat standards. In the countries of the Middle East, a carat weighed 204 milligrams in terms of the metric system.

There was a so-called Arabic carat, it was equal to 223 mg.

And in Egypt, he weighed 195 mg. In the UK, until 1988, a carat weighed 205.4 mg, which differed from the carat standard in Europe. This fact drove the jewelers to despair.

The metric carat was officially adopted in 1907 at the congress of metrologists. Not immediately, but most jewelers appreciated the new standard. Until 1914, it was accepted in most European countries, as well as in the USA and Japan. In 1922, the carat as a measure of weight was introduced into the USSR.

The most important characteristic of a stone is its weight. When it comes to diamonds, in this case, a special unit of measurement is used - carat, abbreviated ct. Jewelers determine the weight of a precious stone on special ultra-precise scales. You can find out the approximate characteristics without them, during a visual inspection, since there is a relationship between mass and size. A special table of carats of diamonds will help in this.

What is a diamond carat?

The appearance of the term is very curious. The word "carat" comes from the name of the seeds of the Caribbean tree: in ancient times they were used to determine the mass of a diamond. In terms of the usual human unit of measure, 1 ct equals 0.2 grams. In total, there are 100 units in a special division scale.

The mass of the stone is measured with high accuracy - up to 0.01 ct. But as already mentioned, approximately this number can be determined by size, if the stone is located separately. It is more difficult to determine the number of carats for a diamond fixed in a product. For this, a formula is used. In the case of the most popular round cut, it looks like this: height * diameter * 0.0061. Depending on the shape of the stone, the formula changes slightly (the last number varies, and instead of the diameter, the product of length and width appears). For example, for a cut "heart" - height * length * width * 0.0059, for a "marquise" cut in a ratio of 2: 1 - height * length * width * 0.058.

Carats of diamonds and the value of the stone

Prices for polished diamonds differ depending on a number of characteristics. Here are the main criteria that affect the cost of a stone:

  • weight and size;
  • color;
  • purity.

Diamonds smaller than 0.01 ct (weighing tolerance) are considered diamonds. The remaining stones are divided into small (less than 0.29 ct), medium (0.3-0.99 ct) and large (from 1 ct). diamonds different sizes evaluated differently. For large stones great attention given to purity and color, in small ones these characteristics are almost invisible, so weight comes first. The evaluation is carried out according to the “Tavernier rule”. Diamond value = carat weight squared multiplied by the base price of 1 ct.

What is a carat?

Diamonds are sold in carats (ct), not to be confused with carats (K), which denote clarity. Since 1913, most states have come to an agreement that carat equals 200 mg, or V5 grams.

Until 1913, the carat had different meanings depending on the country of origin (usually more than a carat weighs now). Indian carat was not equal to an English carat, but french carat different from both English and Indian.

It is important to know this if you have a very old piece of jewelry or you are going to buy it and if you still have the original contract of sale for it, which indicates the carat weight.

Given that an old carat tended to weigh more than metric carat, entered into circulation after 1913, ancient stone three carats in terms of modern standards, most likely, will weigh more than three carats. Today, the term carat refers to a metric carat weighing 200 mg, so 5 carats add up to 1 gram.

Often translated carat weight in points. This is especially true for stones weighing less than one carat. A carat is divided into 100 points.

Thus, if a jeweler says that a stone weighs 75 points, it means that it weighs 0.75, or 3/4 carat. A 25 point stone weighs V4 carats. A 10 point stone weighs 0.1 carats.

The carat is a unit of weight, not size. I would like to emphasize this point especially, since most tend to believe that a one-carat stone has a specific size, and thus, for example, a one-carat and a one-carat stone will have the same size or the same external dimensions. This is not true.

This is easy to show by comparing , and , each of which weighs one carat. First, it has less mass than , but weighs more than .

This means that one carat looks larger than one carat, but looks smaller than identical weight. The emerald, whose mineralogical structure is lighter, has a greater mass per carat, and, whose structure is heavier, has a lower mass per carat.

Let's look at it from the other side. If you compare a cube of wood with a size of 1 cm with the same cube and, it is easy to guess that the cube will be the heaviest, although its volume will be equal to two other materials.

Our iron will be like, wood - emerald, and -. Equal Volumes various materials may have different weight, which depends on their density, also called mass or specific gravity.

Equal volumes of substances with the same density should, accordingly, have approximately the same weight, so in the case of c it turned out that the carat weight corresponds to certain dimensions.

These dimensions, as we have already noted, are based on faceted according to ideal proportions. It follows from this that, subject to the correct cut, the following masses should approximately correspond to 62 sizes. However, it should be remembered that these sizes do not apply to other gemstones.

How does carat weight affect the value of diamonds?

are usually given in terms of one carat. The rarest and highest quality have, per carat, the maximum price, which, as the quality and rarity decrease, will decrease.

For example, a rare one can cost up to $20,000 per carat. Thus, if the stone of the above quality characteristics weighs 1.12 ct, it will be $22,400.

On the other hand, a stone of equal weight, but with less outstanding properties, may cost only $10,000 per carat, or $11,200.

In addition, the price per carat will generally increase from smaller to larger stones, as large stones are rarer and more limited in number.

For example, the same quality weighing 0.5 ct will cost more (in terms of one carat) than weighing 0.33 ct. weighing 3/4 ct will cost more (in terms of one carat) than weighing 0.5 ct.

Thus, price per carat a stone of a certain quality weighing 0.5 ct can be $5,000, while one carat of a stone of the same quality weighing 0.33 ct will equal $3,000. These will cost 2500 (0.5 x 5000) and 1000 (0.33 x 3000) dollars respectively.

Moreover, stones of the same quality weighing exactly one carat will cost much more than those weighing 90 to 96 points. So if you want to buy certain quality one carat stone, but you can not afford it, it is possible that you can afford the same stone, but weighing 95 points.

Such a stone in a fixed form will still give the impression of weighing a full carat. Maybe in the end you will get the same thing that you liked so much.

As you will see later, the increase in price will not be proportional. There are disproportionate jumps. The larger and better the stone (ceteris paribus in terms of overall quality), the less proportionate will be the increase in unit value (per carat).

Price highest quality a 5 ct stone will not be five times the size of a one carat stone. This difference can easily reach tenfold.

What is Estimated Weight?

The term estimated weight of a stone can be heard in response to the question "How big is this?" But this term can be misleading. Estimated weight refers to the apparent size of the stone, which follows from its diameter.

For example, if a stone's diameter matches one of the diamond sizes (which illustrates the stone's diameter with ideal proportions), the jeweler may say that the size will "pull" one carat. But this does not mean that it weighs one carat.

This means that the size roughly corresponds to the size of a perfectly cut one-carat stone. It can weigh less or more, usually less.

As a rule, diamonds are weighed before setting, which makes it possible to accurately determine their carat weight, since the price you pay is calculated from this.

It should also be remembered that price per carat stone excellent quality weighing 96 points will be much less than for a stone weighing one carat or more. That is why it would be reasonable for P1 to purchase a stone of any "approximate" weight, no matter how insignificant this difference may seem.

As you can see, when buying a diamond, it is also important to understand that, since carat is a unit of weight, the cut style can affect its visual size. A one-carat stone cut too finely will appear larger than a stone cut thicker (heavier). Conversely, the diameter of a thick stone will appear smaller.

In addition, having a wide girdle in diameter will seem smaller. If you have a faceted girdle, this allows you to hide a nondescript, faded appearance thick girdle.

However, such a girdle, whatever one may say, still remains thick. The stone will also suffer from appearing smaller in diameter than would be expected given its weight. per carat of such stones will be, respectively, somewhat lower.

Is his carat. However, many are accustomed to consider not only this indicator when calculating the cost. The same 1-carat diamond can be different for different shapes and sizes of the stone. So, for example, the terms “large” or “small” do not carry a semantic load, because weight, grams, carats, diameter and mass determine weight and high cost. Linear dimensions are more often used to determine the length and width, so a separate value was introduced for the stone - the mass fraction and the size range relative to the shape.

What is a carat?

Jewelry making is interesting and challenging, and not many people realize that a beautiful, shiny stone is a labor-intensive job. And this area has its own special terminology. Why is the weight of the stone not determined, but its carat calculated? This is a unit of measurement for jewelry, which is one fifth of the total weight of the stone. Let's say a 1 carat diamond will be equal to a mass of 0.2 grams, and 1 gram of a precious stone will be 5 carats. The name of the measurement value comes from the name of the carob tree seeds. In the research classification of Ceratonia Siliqua (Ceratonia leguminous), even in the era of the Roman Empire, it served as a tool for determining the mass of any small object.

Thus, hundredths began to be used to establish exact size- a diamond with a mass of 40 acres. This means that the carat will be 0.40 of the gemstone in the whole item. Now, an electronic type analytical balance is used to establish the exact size. They allow measurements and measurements down to thousandths of a carat. Only this method applicable to stones that have not been processed by a jeweler. It turns out that in the "gold" business there is a more accurate technology for working with such values.

Calculation symbols

For convenient work with the weight and mass of diamonds, carat values ​​were introduced - it is 1 ct. This is an abbreviation for calculus, which is equal to 0.2 grams. There is a scale of 100 units, which provides for the appropriate divisions of grams to obtain whole numbers of carats. To measure the technology, "high precision" is used, which is equal to 0.01 ct. The number is relative, but for a cut and cut diamond, a different formula is applied to take into account the shape and type of stone.

The most popular cut of a round stone will be treated as a constant, and the formula displays the values: height x diameter x 0.0061. The last number varies depending on the shape of the product. Sometimes, instead of the diameter, approximate length and width data are set (if the stone is not round). Let's say that the height of the cut "heart" will be an exact number, like the width, and last value adjusted to 0.0059. Thus, for the "marquise" the proportion of data will be 2: 1 - the value x length x height x 0.058. As you can see, the formulas can be changed and supplemented if it makes sense to enter linear measurement data.

Share of value calculation

To establish the mass, the jeweler uses linear technologies and calculation methods. The formula is used: M(Kr-57) = D 2 x H x 0.0061 + correction. The D-value will represent the stone's diameter, and the H value will represent its height. Therefore, speaking of mathematical deductions, linear measurements are also found in this art. For example, a 1 carat diamond needs to be measured to obtain diameter and height data. If its shape is round, then you need to correct the original data and those that will be obtained after. The type of cut is also important:

  • Girdle thickness.
  • The size of the culet.
  • Primary processing.
  • Major losses.

In practice, the correction can be up to 17% after visual inspection of the jewel. The buyer should understand that a 1-carat diamond ring will have approximate calculation data, since the error of calculation methods also introduces adjustments and corrections up to 9-10%.

Calculation of the diameter of the stone and the conclusion of the size range

Only for round stones there is a simplified method for calculating carat and weight. This can be done by setting the diameter. Despite the high error, the values ​​are easy to read, established for diamonds different shapes. Below is a table - the size of a diamond in 1 carat relative to its shape.

The table of carat diamonds by shape, weight and size is given in an easy-to-read form for ordinary users. Those who are far from the methodology and essence of the calculation can use the given values ​​when choosing a piece of jewelry as a gift, for example, if you want to buy earrings with 1 carat diamonds. It is also worth paying attention that a lot depends on the type and type of gemstone.

Change in mass relative to diameter

If speak about round shape, then it can also affect the indicators of periodic accuracy. For example, a 1-carat diamond can have different diameters, and fractions often affect these bulge and hardness measurements. Below is another table with diamond weight data and diameter values:

Please note that the typical unit value for carat has a different relative weight than what is indicated in the jewelry store. Such a stone has additional tenths, and the usual weight changes - a diamond of 0.1 carats will be more profitable in price than one that has a weight value of 1.01 carats. The diameter is 2 times larger, and the price is hundreds of times higher. Therefore, you should not immediately buy a carat stone, anyway, its value is higher by a hundredth, but it is better to look at those types that are accurate in size. For example, a 1 carat diamond, the photo of which is shown below.

Weight and transition price of the stone

Naturally, weight affects the value of a diamond. The trend sets a proportional increase in price while increasing carat. But you need to take into account the linear size. The first table shows that all types and shapes of diamonds are different, as well as their respective technical information. In connection with such adjustments, the concept of "transitional mass" was introduced. It is necessary to establish "jumps" in relation to the price of jewelry.

Stones have transitional masses following sizes:

  • Stone of 0.30 carats.
  • Jewelry weighing 1 carat.
  • One and a half carats of stone.
  • 2-3 carats of diamond.

These are the most "running" sizes, so the demand for them is higher, as evidenced by the variable price. No one will change the price for jewelry with a 15-carat diamond, since this is a “luxury” class product.

The cost of stones

You can name the relative value of the stones depending on the brand of the store that sells them. For example, at 0.99 carats the price will be $17,000, and at 1 carat it will be $29,100. That is, the transitional size of a diamond affects the value, which can increase by 70% immediately from an increase in weight of 0.01 carats.

The weighting feature is also taken into account - this means that the diamond weighs more than it seems visually. Such stones are called drawn. It was said above that the density of the stone also affects the cost, and this is exactly what we are talking about here. For example, the diameter of a 1 carat diamond is 6.5 mm according to the table. Its mass corresponds to the parameters, but the diameter is much smaller, taking into account the correct cut - only 6.3 mm. This is a violation of the proportions of the standards, and such stones are sold at a discount.

This leads to the conclusion that the cost is more affected not by the mass, but by the diameter, and its compliance with other measurements. In terms of beauty, the stone loses in price compared to stones correct form. And instead of tens of thousands of dollars, they will give about 8000-9000 dollars for it. This is approximately 500,000 for 1 carat of a diamond (price in rubles).

Weight difference

It is worth knowing that a stone of 0.8 carats will be more expensive than two stones of the same quality of 0.4 carats. Naturally, because large diamonds are very rare, and the reason lies in the analogy of the final weight. Distinguish between the weight and total weight of the stone, they are displayed as follows: t.c.w or ctw and ct. The total weight is indicated in jewelry stores as an average, and a specific weight - for each instance separately.

For example, a product has several stones, which means that total weight will be 2 t.c.w. Stones weigh 1 ct individually and 0.5 ct each for the other two. The total weight can also vary depending on the color, clarity and cut of the product.

Mass fraction of stones and their price

There are diamonds that weigh less than 0.01 carats. When taking into account the error during weighing, the diameter cannot be calculated. They are recognized as crumbs. The remaining stones are divided into:

  • Small, weighing up to 0.299 carats.
  • Medium with a weight of 0.3 to 0.99 carats.
  • Large - from 1 carat and above.

Pricing for large stones considers clarity and color more than diameter. Identical stones in all respects, but different in color, can differ in value by tens of thousands of dollars. For small stones, clarity characteristics are not taken into account, as they are invisible and do not affect the appearance.

Any appraisal examination is carried out according to the “Tavernier rule”, and weight is in the first place. Next, the squares of the mass in each carat are considered, and the whole value is multiplied by the base price for 1 ct.