Which is equal to 1 carat. How is the weight of gemstones measured?

There are many ways to keep your own savings, and one of them is investing in precious stones and metals. The cost of a quality piece of jewelry or ingot never falls, but only increases in price, so such an investment is always a winning one. To start investing, you need to know what is 1 carat in grams and its weight.

The beautiful half of humanity will surely appreciate the unique beauty of jewelry, and for men this is a good way to improve their affairs. But in order to use finance in this type of investment, you need to accurately understand the quality criteria. Do not be surprised if two similar-looking samples have a big difference in price. Even if the smaller one is more expensive, then you need to look not only at its shape, but also at many other features that form its full value.

What is it and the weight of one carat in grams

This is the name of the unit for measuring the weight of precious stones, adopted back in 1907 and now used all over the world. It got its name from the seed of the carob tree - Ceratonia siliqua, which in ancient times was used as a measure for expensive minerals. The seed has always had a constant weight, so it was very convenient to use it. In addition, it is always at hand, it is easy to find and use. Thus, it was even possible to verify the seller. Much has changed since then, but the adopted system of measure has remained, and now we can definitely say how much one carat weighs - only 0.2 grams.

But some countries did not immediately agree with such criteria. Holland recognized the measurement system only in 1911, the USA in 1913. Great Britain held out until 1914, and the USSR stubbornly disregarded the opinions of others and did not accept a single standard until 1923.

Jewelers also have more precise designations, where one ct equals 100 points. With the help of such an easy measure, it became possible to calculate the volume and cost up to a hundredth.

How size and weight compare

The presented gift in the form of a diamond ring necessarily evokes not only delight, but also a desire to understand the size of the insert. It is strongly not recommended to disassemble the decoration for this.

But there is a way out - the severity of each such specimen has long been reduced to its volume and all possible patterns have been calculated. If you have a desire to find out exactly how many carats are in a present or purchase, then you can simply refer to the table. For simplicity, everything is in millimeters.

If the gem is round, then such a table will be relevant, but if its shape is different, then the calculation method will have to be selected differently. This is an approximate version of the values, since when cutting, jewelers try to preserve the maximum initial data. Therefore, the weight may differ slightly upwards.

In the world of jewelry, it would be a big mistake to try to measure in standard categories - specimens larger than 2g are usually so rare that they have a serious value in excess of $ 1,000,000. These piece wonders are named and exhibited in museums, but more often they are in private collections.

If you need to correlate the value and diameter of a ruby, then another table should be used.

For each common subspecies of minerals, there is a table by which you can determine the amount of ct in a piece of jewelry. But most of them are located in jewelry workshops, so you can simply contact a pawnshop or other appraisal firm. So you can find out all the characteristics of the product at once:

• Market value;
• Type of precious stones;
• Approximate purchase price;
• Number of ct.

The main thing is not to try to get the gem out of the jewelry, otherwise it will forever ruin the appearance of the gift, and the stone itself may split or be lost.

Weight measurement history

Valuable gems were inserted into clothes and jewelry that belonged to tsars, so the need to know exactly how much a sample weighs appeared even then. Before the discovery of the modern number system, then it was as far away as before the question of what is one carat in grams.

So in Babylon, they invented a balance in which a weight was placed on the bowl of the apparatus, which needed to be equalized. On the one hand, it could be a diamond or an emerald, and on the other, special weights made of ordinary metal or coins. As soon as the weights were balanced, it was assumed that the weight of the test samples was the same. Traders had to use precise weights that showed the same weight as other traders, otherwise they could be severely punished.

All these criteria were large, so they came up with an additional unit of measurement - gera. She helped to measure small stones and was equal to 0.57 grams.

In Persia, the darik was adopted as the main small unit of measurement, which weighed 5.6 grams. A little later, a denarius weighing 3.85 grams was created. Such a measure in the circulation of money greatly facilitated the life of sellers and buyers, but was still quite large.

It is noteworthy that at the time of the appearance of the darik and the denarius, ct were already and were actively used, but not in Rome and the Greek Empire. They were popular only in Asian countries.

How much is one carat

When the question of how much 1 carat weighs in grams has been resolved - it's time to figure out how much it costs. The price can vary greatly due to many factors:

• Colors;
• Transparency;
• Cut;
• The presence of cracks;
• The presence of inclusions;
• The size.

With the last point of pricing, everything is clear - the larger, the more expensive. Also, for example, when a stone does not have an ideal surface, its score will be several times higher than that of the same product with defects. Color can also affect the price, and quite significantly - they look at the transparency of the stone and glare.

In nature, there are diamonds of blue, pink, yellow, purple, brown and black shades.

The cut is also important. One ct can be sold for half a million rubles or more, depending on the cut and the accompanying metal.

There are several basic types of surface treatments:

• Round;
• Oval;
• Princess.

With the "Princess" cutting method, you need to multiply the height of the sample by its width and length. The result is multiplied by a constant factor of 0.0083. The result is the actual weight of the jewel. Finding out the number is no longer difficult.

The oval cut differs in the calculations - you need to multiply the height by the diameter squared. The result is multiplied by a factor of 0.0062. It is not as economical as the "Princess", but more economical than the round type.

The round diamond is considered the benchmark. Such stones are more expensive, have 57 facets and each of them sparkle. The mass is calculated using a similar formula - the diameter is squared and multiplied by the height. The result is multiplied by a factor of 0.0061. There are also larger samples, they usually have 102 edges, so you cannot calculate them using this formula.

With the last two options, the jeweler tries to leave as much of the original material as possible and subject it to less processing. But at the same time, such species are less valuable. Calculating their carat value will also be more difficult, for this you need to know special formulas. In this case, it is better to turn to professionals.

How it is sold

After the gem has been cut and received a quality certificate, as well as a number or name, it appears in the register of the diamond exchange. It is from there that a sample is first sold, its price is formed according to market conditions, depending on its purity, size and other standard qualities of minerals.

Since the diamond market is the same for all countries, the cost of the same sample will be similar in different countries. The exceptions are those items that are sold by the owners themselves from private collections. In this case, they can demand any amount.

• Small - up to 29 points;
• Medium - from 30 to 90 points;
• Large - from 91 points.

Depending on the category in which the gem falls, its price will change. It is important to understand that a mineral of 89 points will be sold much cheaper than the same one, but weighing 92 points. Visually and in cut, the difference will practically not be felt, but it will already be jewelry from different groups. The difference in price can be 2 or more times.

Then purity and color are taken into account, which also play an important role. If a diamond or ruby ​​is transparent, then their value rises many times in comparison with a specimen of the same size with splashes. Color also affects the cost - the less common such a specimen is in nature, the more expensive it will be sold. The most valuable are red, blue and black diamonds.

The presence of even one, the smallest crack makes the product of poor quality, and its assessment decreases several times. Any defect, even imperceptible to an ordinary person, deprives the stone of the opportunity to be sold dearly.

The place of origin, the approximate age of the mineral and the year of discovery are important for the value. The rating also rises if the gem has some kind of history, especially if it was associated with politicians, kings or just famous people.

It is impossible to try to sell a diamond without a certificate in this market; only those specimens that have been certified by specialists are accepted for auction.

Upon entering the exchange, each lot is checked by its own organization system, the sample data is checked against those indicated in the certificate. If inconsistencies are identified, then it will be removed from sale, and the issuer and owner will have problems.

Amazing and greatest

Among all the gems found, the largest is in the private collection of the King of Thailand. The weight of his copy is 755 carats, it was presented as a gift to the ruler for the fiftieth anniversary of several companies at once.

Slightly smaller and in no way inferior in beauty, the diamond weighs 530.2 grams, it is called "Cullinan I" and is kept in the Tower on the scepter of King Edward VII. Initially, it was a huge 3105 ct diamond, weighing just over half a kilogram, but it was divided into a pair of large, 7 medium and almost a hundred small diamonds. Its feature is the complete absence of chips or any cracks, both before and after cutting.

Another really big one among precious diamonds is called "Incomparable" and has 407.48 ct. Exhibited at the Royal Ontario Museum, Canada.

The smaller diamond is called the "Sun Drop". It was found in Africa in 2010, but it is still considered the largest yellow product - 110.3 ct. In its structure, nitrogen atoms are one of the components, which is precisely what many scientists explain its unusual shade.

Trying to answer the question, 1 carat is how many grams, it is worth thinking about who presented the gift. After all, it is not always worth calculating the cost and value of jewelry - not everyone can afford to purchase gems for millions. Sometimes even the smallest, but sincerely chosen and presented with love, can be much more expensive. And the pawnshop "Avers" can help with this - here you can find different jewelry for the most demanding taste and even for a small budget. One has only to look here.

Precious minerals, thanks to their splendor and shining brilliance, have always attracted the eyes of people and became an object of admiration. However, such expensive stones are made not only by external beauty, but also by their rarity. The cost of unique specimens reaches sky-high heights.

An equally important parameter for setting the price is the weight of the mineral. To measure the mass of precious stones, a non-standard unit is used - the carat, which is well known to jewelers. However, for an uninformed person, the weight of a carat in grams remains a mystery, so before buying an expensive jewelry encrusted with diamonds or sapphires, you should know how much one carat weighs and how to determine the number of grams in a gem.

To measure the mass of precious stones, a carat is used - a unit that has the designation ct and is equal to 0.2 grams. In England, the same value is used to determine the percentage of gold in the setting, but in this case the unit is abbreviated "K".

It is important to note that the dimensions of a gem are not measured in ct, as this is a unit of mass, not dimensions. In addition, the parameters of a jewelry insert largely depend on the method of cutting, with the help of which the crystals take shape.

To determine the value and value of a mineral, one should know how many ct is contained in a particular sample. When buying, do not forget that cleanliness also affects the price, so more does not always mean better.

The history of the appearance of the unit

The history of the origin of the carat as a unit of measurement goes back to ancient times. In the old days, there were no scales, so merchants and jewelery traders had difficulty selling jewelery at their original weight. A unified measurement system was invented, which compares the size and mass of minerals.

To determine the weight of gems, they began to use carato seeds - ceratonia plants, which grew in the area where the extraction of minerals took place. In other countries, acacia grains were used as a weight. However, the name "carat" owes its appearance to ceratonia. The fact is that the fruits of this tree had the same weight - 0.19 grams - regardless of the place of growth and time.

The measurement was formally agreed upon in 1907 during the fourth general conference.

In the USSR, official approval was received in 1922. From that moment on, the mass of jewelry began to be defined in ct.

Views

In the modern world, there are two types of units for measuring the mass of jewelry - metric and assay carat. The first is a measure of the weight of the precious stones, the second determines the purity of the gold alloy.

Metric

Metric carat is a unit of measure adopted in all developed countries. It is the metric ct that measures the mass of unique and dazzling diamonds. The history of the origin of the unit of measurement goes back to antiquity, where the mass of minerals was determined using the fruits of ceratonia, having an identical weight - 189 mg.

The difficulties began when traders found out that fruits differ from country to country. This created inconvenience and caused conflicts between merchants. As a result, the idea of ​​adopting a single unit of mass appeared, but Great Britain opposed this, which adhered to its own metric system. Despite the difficulties, the jewelers soon agreed on a single ct - 0.2 grams.

Assay

This type differs from the metric carat and does not denote a measure of weight, but the purity of a gold alloy. Assay carat was invented in ancient Rome, when the emperor introduced a gold coin that weighed 24 K. A similar coin is in active circulation in the UK to this day. Other countries prefer to use percentages, for example, the 585-carat designation indicates that the jewelry contains 58.5% pure gold.

When using the assay unit of measurement to determine the purity of gold, the following ratio is taken: 24K is the content of pure metal. Therefore, a piece that contains half the gold will have 12K. In Russia, the jewelry industry produces jewelry with fineness 750, 585 and 375 - 18, 14, and 9 K, respectively.

Difference between gold and diamond carats

To answer the question of how diamond carats differ from gold carats, it should be understood that these two definitions are used for different purposes:

• Diamond (metric) carats used to indicate the weight of minerals, which include the famous diamonds. The weight of one carat is 0.2 grams, the designation is ct.
• Gold (assay) determine the amount of pure gold and have the abbreviation K. In some countries, for example, in Russia, jewelry is made with samples that can be easily converted to K.

The system for measuring the weight of gems and gold content dates back to antiquity and is used to this day. In the jewelry industry, carat scales are used to determine the weight in grams with a minimum error. To calculate the carat, there are many tables with which even an ignorant person can calculate the number of grams.

How many grams are in one karate

At the beginning of the 20th century, jewelers agreed on the exact number of grams per karate. In 1907, it was decided to equate the weight of one carat to 0.2 grams. However, not all countries agreed to convert the mass to carats, while continuing to use their own values. The unified standard of the country was adopted in the following sequence:

• France - 1907
• Holland - 1911
• USA - 1913
• USSR - 1923

Following these states, other countries also decided to convert grams into carats. However, a 1 ct gem is a rare and expensive gem. Crystals with a lower mass, less than 0.2 grams, are much more common. But here, too, jewelers did not use standard measures and created their own unit - point. It is found that one ct (0.2 grams) is equal to 100 points.

How the mass and diameter of precious gems are related

Before visiting a jewelry store, a table of the ratio of the diameter, which is measured in millimeters or centimeters, and the weight of the mineral will help you to find out approximately the cost of a stone. It is difficult to find out exactly the mass of a particular specimen, since the gems on sale have different cuts. At the same time, the primary goal of each jeweler is to preserve the weight of the original crystal, so gems of the same diameter can weigh differently.

To understand the intricacies of the ratio of carat and diameter (mm), the table will help:

Similar tables, which exist for each variety of jewelry stones, allow you to find out the number of grams without removing the precious insert from the ring or earrings.

How to identify carats in stone

Many lovers of beautiful jewelry and collectors are interested in how to find out the number of ct in a stone. Undoubtedly, this knowledge will not be superfluous - unscrupulous traders are common, and the risk of being deceived is great.

To measure the carat and roughly determine the cost of a shining pebble, you should remember:

• First of all, you need to find out how many grams the mineral weighs.
• The number of ct directly depends on the diameter of the gem: having the exact figure, you can easily calculate the number of grams.

To determine the number of ct, use one of the following methods:

• Microbalance- an instrument with which minerals are weighed. The measurement accuracy is determined up to thousandths.
• According to the formula. This method works well for loose stones. For measurement, the formula is used: m = (d ^ 2) x h x 0.0061, where m is the mass, h is the height, d is the diameter.

The most convenient method for determining the carat is to use a table, with the help of which, knowing the diameter, the necessary calculations are easily performed.

Square cut minerals carat table ("asher", "princess"):

Carat is a unit of measurement for the weight of precious minerals that has been around for many years. Knowing how many grams a carat weighs, and using special tables, you can confidently go to a jewelry store to shop.

Good afternoon to all connoisseurs of jewelry art and everything connected with it. Today we will talk about how much 1 carat of a diamond weighs in grams. You will find out what is the ratio of the mass of the processed stone to its size, as well as how various precious materials were weighed in the old days. You will definitely love stories related to diamonds. Enjoy your reading!

The history of measuring the weight of minerals and precious metals and what is the cost of one carat

Today we are used to measuring various bulk and solid bodies in grams and kilograms. However, several millennia BC, people used completely different units to measure weight. And to determine the weight of a diamond or other gem, an equal-shoulder scale was used.

Weights made of ordinary stone or ivory (from wealthy merchants) were placed on these scales. For the people of Israel, the Mosaic Law even wrote that merchants were required to have exact weights corresponding to a certain weight. Failure to comply with the Law carried a penalty that could be expressed in an administrative penalty.

The most common units of weight in Israel were the shekel (11.4 grams) and talent (34.2 kilograms). However, when foreign merchants began to import diamonds into the country, it became necessary to introduce a smaller measure to weigh small stones. Then such a unit of measurement as hera appeared.

What was one hera equal to? It corresponded to fifty-seven hundredths of a gram, or about three carats. Of course, not all stones were of this size, but nevertheless Gera made it possible to measure rough diamonds more accurately. The peak of the import of precious materials into the country fell on the period from 1030 to 970 BC, when the people of Israel were ruled by King Solomon, and then by his son. Then the annual income of the tsarist treasury amounted to over fifty billion dollars for the modern monetary equivalent. Even an ordinary inhabitant in everyday life could have precious gems and gold.

In Persia, a darik was used to check the mass, which weighed 5.6 grams. He met the needs of almost all materials. Closer to the first century AD, the Roman Empire began to rise on the world stage. In her money circulation, there was a measure of weight called a denarius, which was 3.85 grams. Interestingly, Greek culture dominated at that time and the Greek language was spoken throughout the empire. However, the monetary measurement of the mass of jewelry was exclusively Roman.

It is worth noting that one carat, as a unit of measurement, already existed during the times of the Greek and Roman empires. However, it was popular only in Asian countries. What is Carat? Carat was the name given to the seeds of a leguminous tree, which were always the same in weight. Since they were always at hand, they were easy to use on the road. The merchants who traded in gems have always had these seeds.

The cost of 1 carat strongly depends on the quality of the stone, its color and size.

What were the carats

Surprisingly, this unit of measurement of the mass of a precious crystal was different in different countries. Sometimes it even measured volume or area. This is what the carat was like in the old days in different countries:

• United Kingdom. In this country, its weight was 205.87 mg.
• Austria. Carat weight 205.3 mg.
• France - 206 mg
• Central Asia - 223 mg.
• Egypt - 195 mg

At first glance, it might seem that the difference is insignificant. However, do not forget that the cost of the mineral is very high, and can reach tens of thousands of dollars per gram.

For example, one gram of fancy red diamond can cost three hundred thousand dollars or more. Therefore, even the smallest inaccuracies in the metric system could lead to serious material losses on the part of the seller or buyer. That is why in 1907 a unified metric system was introduced, which determines the weight of a carat. According to her, the weight of 1 carat was equal to 0.2 grams. This greatly simplified the process of evaluating precious gems. This metric is used in the jewelry industry to this day.

In the European metric system, the unit for measuring the mass of a mineral is denoted by the symbols ct, and in the Russian kar. The troy ounce is also popular when it comes to precious metals. At one time, the smallest unit for determining weight was the grain, which corresponded to 62 mg, or one third of a carat. For a long time, it has been used in pharmacies and jewelry houses. Over time, they got rid of it and only a troy ounce remained.

Diameter to weight ratio

But is it possible to determine the mass of a stone based only on its diameter? When it comes to round stones, then yes. Due to their shape, it is possible to determine their weight in grams by measuring their diameter. There is a special table that contains all the data regarding the weight of a stone of a specific size. We will provide only some information on this issue. For round stones, there is the following weight estimate:

• One millimeter is five thousandth ct.
• Two millimeters - three hundredths of a ct.
• Three millimeters is one tenth ct.
• Four millimeters - twenty-five hundredth ct.
• Five millimeters - half a car.
• Six millimeters - eight tenths of carats.
• Six and a half millimeters - one ct.

With an increase in the diameter of the girdle, its mass will naturally also grow. Although the weight depends on the diameter, but with different cut it will be different for the same type of gemstone. So, when cutting "princess" or "oval", the consumption of waste material will be less than with round cutting, so they are more profitable from a material point of view. Also, less energy is expended on the jeweler.

Calculation of the mass of a gem relative to the cut

• Round diamond... The mass of the sample in this case will be equal to the girdle diameter squared multiplied by the crystal height and multiplied by a factor of 0.0061. Why isn't it calculated using the usual ball formula? The fact is that the stone does not have an ideal rounded shape, but fifty-seven faces, which is why we multiply by a coefficient. For stones with one hundred and two faces, the coefficient will be slightly different.
• Diamond "Princess"... Here, the weight of the sample can be found using the following formula: the height of the pebble multiplied by the width and length, and multiplied by a factor of 0.0083. As you can see, this cut saves more material, so this cut is more profitable.
• Oval cut... Here the calculation is similar as in the case of round cutting. The height of the mineral must be multiplied by the diameter squared and by a factor of 0.0062. Not to say that very economical cutting, but still more material is retained than with a round cut.

So 1 carat is approximately equal to 200 mg.

The largest diamonds in history

The size of a stone is valued as highly as its weight. We present to you, our readers, a list of the largest stones that amaze not only with their magnificence, but also with their impressive size:

1. Cullinan-I was one of those jewels that came from the cutting of a piece of the same name. Each part of it was numbered. The weight of the first Cullinan was 3.1 thousand carats. Its feature was the absence of bubbles and cracks. After crushing the diamond into pieces by the Asscor brothers, 105 stones of various sizes were obtained, the largest weighing 530.2 carats. He became known as the "Star of Africa".

2. The 110.3-carat pear-cut Sun Drop was formed about 3 billion years ago, but was found in South Africa in 2010. The amazing color is due to the nitrogen atoms, which are the constituent parts of the product's mesh.
3. The uniqueness of Card Noir lies not only in the fact that it has 88 carats, but also in its black color. The insurance price of the stone is $ 37 million.

We are sure that this article was very interesting for you, and that you were able to deepen your knowledge of the scale of precious stones. Now you can independently calculate the weight of a gem, taking into account its size and cut. Do you think this information will be useful for your friends as well? Then share this article on social networks and let your friends know the answers to these questions too.

Team LubiStones

How are diamonds measured? Weight plays a major role in evaluating diamonds. The weight of a cut diamond is measured in carats, in abbreviation ct... The word "carat" itself comes from the name of the seeds of the Caribbean tree, which in ancient times served as a natural measure of the weight of diamonds. 1 grain and was 1 carat. Currently, one carat equals 0.2 grams. The carat division scale consists of 100 units, i.e. one carat can be conditionally divided into 100 parts.

The weight of diamonds is measured with an accuracy of 0.01 carats. Stones weighing less than this limit are considered crumbs. The mass of diamonds is measured on special carat scales, and approximately it can be determined by the diameter of the stone.

If the stone is fixed in a piece of jewelry, then you can calculate its mass using a special formula, but there is a possibility of an error. The formula for calculating the weight of a standard round cut diamond: M = (D ^ 2) x H x 0.0061 where M is the mass in carats, D is the diameter, H is the height. However, in order to find out the exact mass of a carat, it must be removed from the jewelry.

Even more approximate figures of the mass of a diamond can be obtained by measuring the diameter of the stone.

Approximate correspondence between the weight and size of diamonds:

	0.03 ct	2 mm
	0.1 ct	3 mm
	0,3 ct	4.3 mm
	0.5 ct	5.2 mm
	1 ct	6.5 mm
	1,5 ct	7.5 mm
	2 ct	8.2 mm
	3 ct	9.4 mm

Large and small stones are evaluated differently. When evaluating large diamonds, experts pay the greatest attention to their clarity and color. It is the special brilliance that attracts its lovers in the diamond.

Small stones are rated by weight, not by their individual qualities. There are three weight groups of diamonds:

Small - diamond weight less than 0.29 carat

Average - diamond weight from 0.3 to 0.99 ct

Large - diamonds weighing more than 1 carat.

As a rule, large diamonds weighing more than 6 carats are sold at auctions. And stones over 25 carats have their own names.

Diamond grading

It is produced according to the so-called "Tavernier rule": the cost of a gem is equal to the product of the square of the mass (weight) of the crystal in carats by the base price of one carat. So, a 2-carat diamond is 3 times more expensive than a 1-carat stone, 3 carats - 10 times more expensive than a one-carat diamond. This "progression" grows up to 5 carats. A 10-carat diamond is valued at 100 times more than a 1-carat diamond.

For several years now, the best-selling diamond in Russia has been the 0.1-carat stone, which is called the “folk diamond”. The average cost of such a stone is about 10,000 rubles. With the same average characteristics, a 0.5-carat diamond can be purchased for 160-180 thousand rubles, and a one-carat diamond will cost 500,000 rubles.

Of course, these prices are conditional, since everything depends on the specific stone, its purity and cut shape. The table below shows the approximate weight of a diamond in relation to its diameter (round cut).

Most often, round-cut diamonds are found in jewelry. it is the most common. However, precious stones are cut in a different way. A diamond can have a pear-shaped, emerald, heart-shaped, oval cut, and, with different sizes, have a different carat. Note the various cut shapes.

Below we give formulas for calculating the carat of diamonds... However, do not forget that the calculation using these formulas cannot be unconditional and absolutely accurate - finding the mass of a stone, based on its geometric dimensions, is based on the ideal cutting characteristics. The slightest deviation leads to inaccurate results, and if we take into account that the level of modern cutting is far from perfect, then we can only talk about the approximate value of the mass.

Having determined the weight of your diamond, you can contact our service

Carat is one of the characteristics that affects the value of gemstones and jewelry in general. However, for many, this term does not mean much. Therefore, before the planned purchase of jewelry or before investing money in precious minerals, it is worthwhile to figure out what constitutes a jewelry standard of weight.

The history of the origin of the jewelry measure

The extraction and sale of precious stones originated many centuries ago. To sell gems profitably, it was necessary to somehow determine their weight. The first standard of weight was the grains of cereals that grew on a particular continent. The grains were selected in such a way that each grain was of the same weight and size.

The homeland of most precious minerals was the countries of the Ancient East, where carob seeds - ceratonia were considered the standard of weight. This plant was the ideal unit of measurement for the ancient Romans, since regardless of the growth process, each tree produced identical grains, weighing 189 mg each. The carob tree is considered the founder of the term "carat".

The Mediterranean countries used acacia seeds, which are relatively uniform in size and mass, to determine the weight of stones and gold. When Emperor Constantine ruled the Greeks, the solidus coin was minted in the country. The weight of this gold coin was equivalent to 24 grains of acacia, which laid the foundation for the emergence of the term "carat fineness" as a definition of the purity of the metal.

It is also known that in European countries the weight of precious stones was determined using barley grains, which were the smallest of the grains in the area. There is a version of a coral tree growing in hot countries, the grains of which are almost equal to the weight of a carat. However, such a position of the emergence of a jewelry unit of measure is the least likely.

Measurement systems of different countries

Until the beginning of the 20th century, there was no single system for measuring the weight of precious stones. Each "point of sale" of high-value minerals around the world used its own measure. Because of this, confusion arose when trying to determine the cost of a gem, because the difference in weight sometimes reached 0.026 grams, which is quite significant. In Russia, it is considered, since 1922, for 1 carat 200 mg or 0.2 g.

Metric carat

In 1907, in Paris, the IV General Conference on Weights and Measures adopted the official measure for the weight of precious minerals i - carat, which was equivalent to 0.2 grams or 200 mg. The metric carat quickly became the standard of jewelry measure for most countries.

English carat

In England, the local measure of the weight of gems was 205.4 mg. The entire weight system of the country, including the jewelry one, was based on the troy pound - the main British unit. This unit, in turn, was divided into several others, eventually leading to a troy grain equal to 64.79 mg. At the same time, the carat was equal to 3.17 troy grains until 1888. After the Department of Commerce determined the weight of the English measure, as 205.3 mg. Since 1914 England has been using the world metric system.

Arabic carat

The canonical karat or kirat was used in Iraq. There, the jewelry unit of measurement was equal to 1/14 of the weight of the local silver coin - the dirham, which is proportional to 223.2 mg. The kirat of Syria, Egypt and Mecca differed significantly in weight, accounting for 195 mg. At the same time, the Egyptian kirat was put in relation to its own measures of weight - bakil and shamun. The kirat of Asia Minor was also different, equal to 204 mg.

Alternative measures of weight

In addition to the generally accepted carat weight system, jewelers use the following terms:

• A jewelery grain is a unit equal to ¼ carat or 50 mg. It is no longer used today. Earlier, the weight of pearls was determined with the help of a grain.
• A gram is a unit used in raw material purchase and sale transactions. In jewelry, it is important to know how many grams are contained in one carat in order to estimate the approximate weight of the stone that can be obtained from this raw material.
• Momme is a weight measure used only by the Japanese to measure the mass of pearls. Momme is equal to 18.75 carats.

The carat weight of a stone is one of the main criteria for evaluating the value of a precious mineral. Therefore, in order to establish the price of a gem, measurements are carried out with maximum accuracy. In abbreviated form, the carat of the stone is denoted "ct".

Price of a carat of precious stones

Precious stones and jewelry with them today are considered not only an attribute of a secular society, but also a profitable financial investment. Some minerals can cost tens or hundreds of thousands of dollars. Diamonds are holding the price peak, although some rare minerals are confidently overtaking diamonds in this struggle for leadership.

Top five gems

Despite the large number of scientific classifications of minerals based on various signs, there is still no clear separation of stones. Indeed, sometimes a flawless rare gem is several times higher than the cost of a diamond of not the best quality. However, the conditional five precious minerals have been identified to top the list of the most expensive stones:

• ... The cost of 1 carat of a diamond starts at 15 thousand dollars, being determined according to a number of criteria. But there are also so-called "folk" diamonds - stones of 0.1 ct at a price of about 10,000 rubles. The carbonado is considered inexpensive - a black diamond with an average cost of $ 150 / ct. The best stones reach $ 500-600 / ct.
• ... Estimated from 350 $ / ct. This applies to stones of the lowest quality. The ideal emerald starts at $ 8500 / ct, increasing the price in proportion to the size of the nugget - a faceted emerald of the highest quality weighing from 5 ct costs about $ 15000 / ct.
• ... Poor quality red corundum sells for $ 100 / ct. But if a red nugget is assessed as flawless, then the price per carat of such a stone soars up to 15 thousand USD.
• ... The most expensive corundum is cornflower blue. The heated mineral is sold from 300 to 1000 $ / ct. Non-heat treated mineral starts at 1000 $ / ct. An orange sapphire is considered a rare gem -. Its cost starts at $ 130 / ct. A collector's item weighing more than 5 carats can cost about $ 30 thousand.
• ... A 3-5 carat stone of inferior quality sells for $ 600-2500. The best examples sell for up to $ 22,000 / ct. The record price for a carat of Russian alexandrite sold at auction was $ 70,000.

The five stones that top the lists of the most expensive minerals in the world are far from the last selection of beautiful gems belonging to the precious category.

Video about the cost of 1 carat of a diamond:

Diamond quality rating:

Popular precious minerals

The list of fascinating stones can be continued indefinitely, but the highest positions are occupied by:

• - the average price is $ 500 per carat. The best samples go up to $ 1000 / ct.
• - the most valuable non-refined imperial yellow stone is estimated at $ 70-500 / ct, pink - from $ 500 to $ 3500 / ct.
• - green palette - $ 100-150 / ct. Complex color combinations are twice as expensive.
• - 200-300 $ / ct. Large specimens reach $ 1000 per carat.
• - depending on the variety and quality - from $ 50-100 to several tens of thousands per carat.
• - the price starts from $ 20-30 / ct, reaching $ 1000 / ct for rare copies.
• - from 20 to 100 $ / ct.
• (smoky quartz) - 900-8000 rubles per stone.
• - from 600 to 2000 rubles per carat.

Artificial ones are very popular - they shine en masse in jewelry, successfully copying diamonds. But their cost is penny - $ 10-15 for a bag of 100 pieces of medium-sized stones, $ 50 for a similar volume of multi-colored raw materials.

The ratio of weight and size of the stone

There is a misconception that the weight of a gem determines its size. But the physical and chemical nature of minerals is arranged in such a way that different gems of the same weight have different sizes due to different densities. Compared to a diamond, a one-carat sapphire or ruby ​​will be smaller, but an emerald will be larger.

Another indicator that determines the size of the stone is the cut. According to this criterion, even diamonds of the same weight differ in size.

These sizes are indicated for cut group A. For other cut groups, sizes may vary slightly.

So, a one-carat diamond will have completely different sizes, depending on:

• Circle. The most popular cut. The diameter of such a stone is 6.5 mm. Round diamonds, regardless of the number of facets, are the most expensive, since the lion's share of their precious weight is lost during processing.
• "Marquis". The cut, which was born thanks to the favorite of the King of France. The diamond, reminiscent of the smile of the Marquise de Pompadour, measures 9.8 * 5.6 mm.
• Square. This shape implies various types of cut, the most popular of which are "Princess" and "Asher". Size - 5.55 * 5.55 mm.
• Oval. Size - 7.7 * 5.9 mm. The brilliance of oval diamonds is identical to that of round diamonds, but the former benefit from their size.
• "Cushon" and "Radiant". Square cut with beveled edges, stone size 6 * 5.5 mm.
• "Pear". This shape is a tandem of two other shapes - the circle and the "Marquise". The size is 8.6 * 5.8.
• Heart. A cut designed to hide the natural imperfections of a diamond, measuring 6.7 * 6.5 mm.
• "Baguette". A one-carat stone has a size of 7.7 * 4.5 mm. The brilliance of this shape overshadows the brilliance of round diamonds.
• Emerald. Size - 6.4 * 4.9 mm. This type of cut is only suitable for flawless stones. Otherwise, this form will highlight all the flaws. Emerald shapes shine brighter than round ones, but the latter better convey the play of color.

If we talk about the weight of diamonds, the carat value plays a decisive role only in the evaluation of small stones. When determining the cost of large specimens, first of all, they take into account the indicators of purity and color.

Karat value of precious metals

The term "carat" is also used to define the purity of a precious metal or the amount of a precious metal in an alloy. Assay carat is designated by the letter "K" or "kt".

Today, countries such as the USA and Canada use the carat sampling system. The pure metal alloy has a fineness of 24 carats. Depending on the proportion of the content of the noble metal in the alloy, samples are distinguished:

• 23K - the mass of the noble metal is 0.958 of the weight of the alloy.
• 22K - 0.916.
• 21K - 0.875.
• 18K - 0.750.
• 14K - 0.583.
• 12K - 0.500.
• 9K - 0.375.

In the countries of the former Soviet Union, since 1927, the metric system of measures has been used, which determines the samples of different alloys by the ratio of the amount of noble metal in 1 mg of the alloy. Various samples have been identified for platinum, gold, silver and palladium. The karat test can be easily converted to the metric system in two simple mathematical operations. To do this, the carat test is divided by 24 and multiplied by 1000.

The metric probing system is used by dozens of countries in Europe and the world. Ireland uses both tests to mark the product. England affixes a metric measure to the hallmark, but the description of the product (exclusively made of gold) also allows a carat test.

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