What is a jewelry carat? Gemstones and their carat weight
Gems and some other gifts of nature in carats. The roots that gave rise to this definition go back centuries. One common belief is that weight was originally measured by acacia seeds. This plant grew in the Mediterranean. The pods of the shrub are called "little horn", and in Greek pronunciation - "carat".
Another suggestion points to a coral tree. The weight of its seeds is approximately equal to the weight of the average one. The Romans also measured jewelry using plant seeds. 24 grains served as a weight.
In Greece, coins were minted whose weight corresponded to 24 acacia seeds.
Carats measure precious stones, the proportion of gold in the alloy, and pearls. It was quite difficult to measure the value of the latter and estimate it. It depended on many factors. Even the batch of grown pearls mattered.
Carats and grams
These were all just approximate values. They could vary depending on the location of the tree that grew, the type of pods, and even the humidity of the air. Later they began to measure it in , but even then there was no officially established value of how much one carat weighs. Even within the territory of one country, measurement limits from 0.188 to 0.213 grams were recorded.
When trade began to acquire global proportions, the need arose to come to a single measurement value.
Parisian merchants were the first to try. At a meeting of the Precious Chamber in 1877, an official measure was proposed: one carat corresponded to 0.205 grams. However, the international community did not support this initiative. Later, in 1907, the General Conference was held in Paris, which dealt with issues of a unified system of weights and measures. One of the agendas was to determine the official carat size. From now on, 1 carat is equal to 200 milligrams.
However, not all countries supported the establishment. The French had to be active in attracting the world community to create a standard of measures. Resolutions were adopted in some countries, canceled in others, and simply ignored in others. But by 1914, the French committee had already gained weight in the eyes of representatives of many countries. And finally, the actions were crowned with success. In 1930, the proposed measure of the weight of precious stones was finally established and became an international unit of measurement.
When the word “carat” is heard, our contemporary understands: we are talking either about a measure of the weight of precious stones (one carat is equal to 0.2 grams); or about, adopted in Britain (pure gold conventionally contains 24 carats).
In earlier times, the concept of karat was interpreted much more broadly, and it was much more difficult to use the term.
In the beginning a tree grew...
...and the tree was ceratonia. Ceratonia fruits - bunches of long, curved pods resembling goat's horns with seeds of the same size and weight - are loved by people for their sweet taste and chocolate aroma. The ancient Romans, marveling at the natural uniformity of ceratonia seeds, introduced a mass measure equal to one ceratonia seed. Of course, the seeds themselves were used as weights.Carat is a modified cerátiοn, which in Greek meant “like a horn”, and in modern terms it became “ceratonia”. The size of the Roman carat was 0.189 grams - but this value was not maintained everywhere.
Different countries - different carats
Ceratonia does not grow everywhere, but where it grows it differs in the size of its seeds from the fruits of other regions. How else can we explain the difference observed in the definition of carat right up to 1907? The Arabic carat, which gained recognition in Mesopotamia, was equal to 0.2232 grams. In Egypt, Syria and Arabia, a carat weighed only 0.195 grams: apparently, ceratonia grew in these areas, producing small seeds.
In the territory from the southern coast of the Black Sea to the northern borders of Syria, the carat weighed more - 0.204 grams. In England, until the end of the 18th century, the carat size fluctuated between 205.3 and 205.4 milligrams - which confused continental jewelers. In general, carats weighing from 0.1885 to 0.2135 grams were in use, and discrepancies could be observed even within the same jewelry and shopping center.
And finally, in 1907, in Paris, at a representative forum of metrologists, it was decided to simplify the situation, equating a carat to two hundred milligrams, which in digital writing looks like 0.2 g or 200 mg.
The jewelers wiped the sweat from their foreheads and sighed with relief: the attempt to standardize accounting weight units was a success! They had made efforts of this kind before, but with the introduction of the same grain they fell into the same trap. The gran, intended to replace the carat, which was exotic for northern areas, was equated to the mass of a barley grain; but barley is different everywhere!
Karat is not karat's brother!
England, which hates everything French - and the metric system of measures was invented by the French - decided to conduct the assay business in duodecimal (rather than decimal) notation. And to further confuse the unfortunate inhabitants of the continent, the fractional measure of the concentration of gold in the alloy was called... also a carat!One hallmark carat is one twenty-fourth of the gold in the alloy. Nine-karat gold is an alloy, the amount of gold itself in which is calculated by the formula: weight of the product in grams: 24 x 9 = the required number. In eighteen-carat gold, the ratio of pure gold is 18:24 or 3:4, that is, three quarters. Simple! Especially for those who easily handle shillings and pence. True, you still can’t do without grams...
The only thing the French were able to do in their Chamber of Weights and Measures was to force the British to designate weight and assay carats differently. A weight carat is ct, an assay carat is K. In England they laughed sarcastically at the French innovation - after all, it is clear from the meaning which karat we are talking about in which case, why invent some designations, but in the end they agreed.
Weight carat is also not simple
The introduction of carats rounded to 200 milligrams also did not proceed quickly. It took the global jewelry community a quarter of a century to get used to the idea of a single karate that was easy to calculate. True, the previously made inserts began to weigh more - after all, the new carat was generally slightly thinner.So it is not surprising that today the carat weight has been divided into one hundred points, and the mass of especially valuable stones (especially small diamonds) has begun to be expressed with high accuracy.
Weight and size of the stone
The consumer does not particularly care how many carats and points his stone weighs. It is much more interesting to visually imagine the size of a cut gem, because the amount of light passing through the crystal depends on the area of the faces.In addition, different minerals have different densities, and a three-carat ruby is not the same size as a three-carat topaz. For sophisticated lovers of cut gems, tables have been compiled in which the cut shape and carat weight are compared with the geometric dimensions of the stone.
Unfortunately, the accuracy of such tables is low: manual cutting allows for very significant deviations in the shape of the product from the theoretical ideal. And the density of the mineral is not always the same: for example, one cubic centimeter of pomegranate can weigh either three and a half or four grams.
Thus, the mass of a stone, expressed in carats, is an important characteristic, but far from determining its aesthetic value and monetary value.
There are many ways to store your savings, but one of the most common is investing in jewelry stones, because over time the value of good jewelry does not fall, but grows. But the mass precious mineral expressed in carats, but how much is it?
Stone connoisseurs can figure this out easily, but guess what? to the common man when he hears about the 2 carat diamond.
What kind of stone is this, how much does it weigh and what is its cost? Let's look at this issue in detail.
What is carat
Here is a definition posted on official resources. A carat is a jewelry weight standard used to determine the weight of precious stones, denoted by ct and weighing 200 mg. The British use the same value to determine
percentage
pure gold in the alloy, but then the abbreviation K is used. It is important to understand that the size of a mineral is not indicated in ct, so different jewelry stones with the same mass may have differences in size, because they have different densities. The second important detail is the cut. There are several official processing methods that can give a product of the same mass completely different shapes.
It should also be remembered that the purity of the stone, its rarity, is valued no less highly
, so a small, lightweight pebble can be much more expensive than a large, but of lower quality. Types of carats
Today, two types of carats are recognized: metric and assay.
Until the beginning of the 20th century, in all countries one carat had a different value in grams, which created huge inconveniences in international trade.
However, the world was not yet so global, so local traders focused on their population, making weights according to the parameters accepted by the state.
The next limiting factor was Great Britain, which had many colonies and forced them to use their metric system. However, the jewelers managed to agree that the carat standard would be 200 milligrams.
This parameter was officially recorded and is still used today.
Assay This unit of measurement is actively used by America and Great Britain.
Other countries are more willing to use gold fineness expressed as a percentage. For example, a 585 ring means that the alloy contains 58.5% gold, the rest copper and other metals.
When using carat for the test (abbreviation K), the value taken as a basis is that pure gold without impurities is 24 K. Accordingly, an alloy where only half of the noble metal will have 12 carats and so on. Americans consider a product of 10 K or more to be jewelry, but in England the bar is lowered to 9 K.
Both systems for determining the proportion of gold in an alloy have the right to exist, and using a calculator you can convert one measurement system to another.
What size stone corresponds to carat
Jewelers have tables that allow you to determine the weight of a gemstone by size and vice versa. Often in this way you can identify fakes without even using a microscope or magnifying glass. However, the data is somewhat averaged and may differ slightly from reality in one direction or another.
A table that allows you to correlate the weight and size of a diamond, subject to a classic cut: | 0,1 | 0,2 | 0,3 | 0,4 | 0,5 | 0,7 | 0,9 | 1 | 1,25 |
Ct | 3 | 3,8 | 4,5 | 4,8 | 5,2 | 5,8 | 6,3 | 6,5 | 6,9 |
Diameter (mm) | 1,8 | 2,3 | 2,7 | 3 | 3,1 | 3,7 | 3,8 | 3,9 | 4,3 |
Height (mm)
A table that allows you to correlate the weight and size of a diamond, subject to a classic cut: | 0,01 | 0,05 | 0,15 | 0,34 | 0,6 | 1,05 | 1,7 | 2,3 | 4,75 |
Ct | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 10 |
Another table that allows you to correlate the mass of a gemstone (ruby) and its diameter:
Similar jewelry tables exist for all jewelry stones, so a specialist can find out the weight of the mineral using a micrometer without removing it from the jewelry.
However, adjusted for error, the so-called estimated weight is obtained. How much does a carat weigh?
Today we can answer this question unequivocally, because the standard is stored in the Museum of Weights and Measures.
- In 1907, after lengthy consultations, it was decided to express 1 carat in 200 milligrams. However, not all countries made a decision on this issue immediately, continuing to use their values.
- Here is the history of the adoption of a single standard by leading powers:
- 1907 – France;
- 1914 - Great Britain;
- 1923 – USSR.
Other countries focused on their strategic partners, making decisions after them.
However, a stone weighing one carat is considered expensive and quite rare, so minerals that do not reach 200 milligrams are much more common in jewelry. Jewelers found a way here, too, not to resort to the classical metric system of calculating masses, but came up with their own unit - the point.
It was agreed that 100 points would equal 1 carat. Accordingly, the weight of a gemstone is determined to the nearest point or hundredth of a carat.
How much does a carat of diamond cost?
The price of a gemstone is influenced by its purity and size, which is converted into mass. There are 3 categories of diamonds:
- small – up to 0.29 ct;
- medium - from 0.3 to 0.9 carats;
- large - from a carat and above.
When moving from one category to another, the price can double, because one of the main components is rarity, and to obtain a stone weighing 100 points, you need to process at least 250 tons of rock, so a large mineral is a rare find.
After receiving the certificate, the diamond enters the registers of the diamond exchange, which puts it up for sale, and the value is determined by the laws of the market.
Therefore, the price of the mineral in different countries will be similar, with the exception of jewelry sold by the owners themselves or counterfeits.
- Examples of prices: rare one carat diamond
- and a little more will be purchased for no less than $120,000 per carat; stone of the same mass with lower values
purity will go for $10,000 per ct.
It is worth understanding that a mineral weighing 96 points will be at least 2 times cheaper than a diamond weighing 1.02 ct, this is due to a different category, although visually they will be practically no different. Diamonds of the first category are used for inserts into gold and platinum rings
, so a small stone of 0.1 carat can cost 10,000 rubles, hence their name - folk.
History of origin
Both types of karats originate from ancient Rome.
Metric carat A unique plant grew on the territory of the empire - ceratonia.
However, on different continents, ceratonia had its own differences, which was expressed in the mass of the seed, hence the different indicators in grams.
And only about 100 years ago it was possible to reach an agreement, rounding up or down various standards to an even and convenient value - 0.2 grams.
Hallmark carat Roman Emperor Constantine introduced gold coin
solidus, which was the same throughout the territory and weighed 24 carats of pure gold. Scientists cannot answer unequivocally whether the British took this fact for their metric system, but since then the 24 K standard means pure gold.
Although modern experts are inclined to believe, that 24 is easily divided into parts, so the sample did not need to be expressed through a fraction, as was done before. Carat is a term used in Britain and the United States to describe the fineness of gold and other precious metals. In simple words).
, this value shows the amount of pure gold in the product, with the highest standard in carats being 24K (
which corresponds to 999 in the metric system What is the difference between carats of gold and gemstones? Before we begin to talk about all the details of the carat system for measuring the purity of precious metals, we should put an end to the confusion of terms. The fact is that the term “carat” is used not only as a gold standard, but also to indicate the weight of precious stones. In fact, this is not even one term, but two completely different words, with different meanings. Here the translation from
- in English into Russian. In reality the picture looks like this:
- Karat is a unit of gold in the purity of the alloy.
Carat
is a unit of mass used to measure the weight of gemstones and pearls. 1 carat = 200 mg.
Why do you need a gold sample?
It should be noted that the high content of pure gold in an item does not mean that the jewelry will be better, brighter or more beautiful. To explain this concept, you need to understand why I mix gold with other metals in the first place. The fact is that gold is an unusually soft metal. It is so soft that it can be molded almost by hand. Because of this property, products with a high content of pure gold do not withstand practical and everyday use. Such jewelry is very susceptible to various deformations and scratches. It is for these reasons that jewelers in most cases use various gold-containing alloys, which are designed to increase the stability of products.
How to convert carats to our metric standards?
This information will help us in this matter:
- 6 carats is 25% pure gold;
- 8 carats- This 333 sample and accordingly contains 33.3% pure gold;
- 9 carats- This 375 fineness – 37.5% pure gold;
- 10 carats is 41.7% pure gold;
- 12 carat- This 500 sample – 50% pure gold;
- 14 carat- This 585 fineness – 58.5% pure gold;
- 18 carat- This 750 sample – 75% pure gold;
- 22 carats is 91.6% pure gold;
- 24 carats- This 999 sample – 100% gold.
How to distinguish a real gold product from a fake?
- First of all, you should pay attention to the hallmark of the jewelry. If it is illegible or too worn out, this may give rise to doubts.
- Pay attention to the weight. Gold is a very heavy metal, and if the item seems too light to you, then there is a chance that it is just gilded.
- Another factor worth considering is price. Remember that the price of the product must be within the market price. If you are offered something too cheap, you should take a closer look to find the catch.
- Also take into account the softness of gold. There is always the opportunity to check the product for deformation.
- The best way to check is the acid test. The fact is that gold does not react to nitric acid. Other metals foam or dissolve when they come into contact with acid.
- Well, or if you are an avid pirate, you can try your gold doubloons “by the tooth” - if a dent remains, it means it is gold of the highest standard. Well, or they slipped you chocolate in colored foil, but then you are no longer a real pirate.
Good afternoon to all connoisseurs of jewelry and everything connected with it. Today we will talk about how much 1 carat of diamond weighs in grams. You will learn the ratio of the mass of a processed stone to its size, as well as how various precious materials were weighed in the old days. You will definitely enjoy stories related to diamonds. We wish you pleasant reading!
The history of measuring the weight of minerals and precious metals and what is the cost of one carat
Today we are accustomed to measuring various bulk and solid bodies in grams and kilograms. However, several thousand years BC, people used completely different units to measure weight. And to determine the weight of a diamond or other gem, equal-arm scales were used.
Weights made of ordinary stone or ivory (from rich merchants) were placed on these scales. For the people of Israel, the Mosaic Law even stated that merchants were required to have precise weights corresponding to a certain weight. Failure to comply with the Law carried with it punishment, which could be expressed in administrative penalties.
The most common units of weight in Israel were the shekel (11.4 grams) and the 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 the hera appeared.
What was one hera equal to? It corresponded to fifty-seven hundredths of a gram or approximately three carats. Of course, not all stones were of this size, but still the ger made it possible to measure rough diamonds more accurately. The importation of precious materials into the country peaked between 1030 and 970 BC, when the nation of Israel was ruled by King Solomon and then his son. At that time, the annual income of the royal treasury amounted to over fifty billion dollars in modern monetary equivalent. Even an ordinary resident could have precious gems and gold in his everyday life.
In Persia, a darik was used to check mass, which weighed 5.6 grams. It satisfied the needs of the body kit of almost all materials. Closer to the first century AD, the Roman Empire began to rise on the world stage. In its monetary circulation there was a measure of weight called a denarius, which was 3.85 grams. Interestingly, Greek culture was dominant at that time, and the Greek language was common 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 a carat? Carat was the name given to the seeds of the pod tree, which were always the same in weight. Since they were always at hand, they were easy to use on the road. Merchants who traded gems always had these seeds.
The cost of 1 carat greatly depends on the quality of the stone, its color and size.
What were the carats?
Surprisingly, this unit of measurement for the mass of a precious crystal was different in different countries. Sometimes it was even used to measure volume or area. This is what the carat was like in the old days in different countries:
- Great Britain. In this country, his 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 may 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 a fancy red diamond can cost three hundred or more thousand dollars. Therefore, even the smallest inaccuracies in the metric system could lead to serious financial losses on the part of the seller or buyer. That is why in 1907 a single metric system was introduced to determine carat weight. According to it, the weight of 1 carat was equal to 0.2 grams. This has greatly simplified the procedure for evaluating precious gems. This metric is used in jewelry production to this day.
In the European metric system, the unit of measurement for the mass of a mineral is designated by the symbols ct, and in the Russian car. The troy ounce is also popular when it comes to precious metals. At one time, the smallest unit of weight was a grain, which corresponded to 62 mg or one third of a carat. For a long time it was 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? If this applies to round stones, then yes. Thanks to their shape, you can determine their weight in grams by measuring their diameter. There is a special table that shows all the data regarding the weight of the stone and the specific size. We will provide only some information on this issue. For round stones there is the following weight estimate:
- One millimeter is five thousandths of a karat.
- Two millimeters – three hundredths of a car.
- Three millimeters is one tenth of a carat.
- Four millimeters – twenty-five hundredths of a karat.
- Five millimeters is half a car.
- Six millimeters – eight tenths of a carat.
- Six and a half millimeters - one carat.
As the diameter of the girdle increases, its weight will naturally increase. Although the weight depends on the diameter, with different cuts it will be different for the same type of gemstone. Thus, with a “princess” or “oval” cut, the consumption of waste material will be less than with a round cut, so they are more profitable from a material point of view. It also requires less effort from the jeweler.
Calculation of gem weight relative to cut
- Round diamond. The mass of the sample in this case will be equal to the diameter of the girdle squared multiplied by the height of the crystal and multiplied by a factor of 0.0061. Why is it not calculated using the usual ball formula? The fact is that the stone does not have an ideal round shape, but fifty-seven faces, which is why we multiply by a coefficient. For stones with one hundred and two sides, 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 type of cutting preserves more material, so this type of cutting is more profitable.
- Oval cut. Here the calculation is similar to that for 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 cutting is very economical, but still more material is saved 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, which amaze not only with their magnificence, but also with their impressive size:
- Cullinan I was one of those jewels that came into existence through the cutting of a piece of the same name. Each part of it received a number marking. The weight of the first Cullinan was 3.1 thousand carats. Its peculiarity was the absence of bubbles and cracks. After the Asskor brothers crushed the diamond into pieces, 105 stones of different sizes were obtained, the largest weighing 530.2 carats. They began to call him the “Star of Africa.”
- The 110.3-carat yellow pear-shaped Sundrop was formed about 3 billion years ago, but was found in South Africa in 2010 year. The amazing color is due to nitrogen atoms, which are part of the product's mesh.
- What makes Card Noir unique is not only that it is 88 carats, but also its black color. The insurance price of the stone is $37 million.
We are sure that you found this article very interesting and that you were able to deepen your knowledge of gemstone weights. Now you can independently calculate the weight of a gemstone, taking into account its size and cut shape. Do you think this information will be useful for your friends? Then share this article on social networks and let your friends also know the answers to these questions.
Team LyubiKamni