differenza

What are carats?

How many carats is your diamond in? And how many karats is your gold ring instead? For those who are not a jewelry expert or do not know the basic rules of the world of jewelry, the carats are a big mess. The carats that are the unit of measurement needed for precious stones and pearls, in fact, are a completely different thing from the karats that refer to gold. Did you know? In English, everything is easier: the carats that measure diamonds start with the letter C while those for gold start with the K. In other languages, however, it is written the same way and everything is more complicated.

This is why we must be careful not to confuse the different concepts: the carats of diamonds (or rubies, emeralds, sapphires, etc.) with the karats that are related to gold. Here’s how to distinguish.

Diamante a cuore di Recarlo
Diamond in the heart of Recarlo

The carats of the stones

The carat (the abbreviation is ct) is a unit that indicates the mass of a stone or pearl. Carats are used for convenience, after in past each country regulated itself differently for centuries. For those who traded in diamonds or other stones it was therefore difficult to work. In Florence, for example, the basic unit of measurement was equivalent to 197.2 milligrams, while in London to 205.49. After much discussion, in the end, in 1907 it was decided to adopt 200 milligrams as a carat measure. A single carat, therefore, equals one fifth of 1 gram.

Anello con diamante bianco ovale da 31,82 carati
31.82 carat oval white diamond ring

Now you know exactly how much the diamond on your finger weighs: divide the number of carats by five and you will have the weight in grams. Or, more easily, in milligrams, since it is not common to wear a diamond that weighs 5 carats (and therefore 1 gram). for this reason the carat is divisible into 100 points of 2 milligrams.

Anello di Van Cleef & Arpels a forma bombata con diamanti
Van Cleef & Arpels rounded shape ring with diamonds

By the way, why is the carat called so? The origin seems to be linked to carob seeds. The word carat derives from the Arabic qīrāṭ قيراط, which however is derived from the Greek kerátion κεράτιον, which indicates carob seeds. And these seeds were used to weigh jewels, thanks to their always regular shape. Then the term carat was used in Italy and later in the rest of the world. The use of the carat unit of measurement to weigh diamonds dates back to 1570.

Selezione dei diamanti nel laboratorio di Antwerp (Anversa)
Selection of diamonds in the Tiffany laboratory in Antwerp

The karats of gold

The carats of diamonds, precious stones and pearls refer to weight. The karats of gold, on the other hand, indicate the percentage of yellow metal present in a jewel, its fineness. The term karat has prevailed among the many systems adopted in the past and, in particular, on the measurement of pounds and ounces, which are still used for the weight of gold, platinum or silver. So why this confusion? Simple: the ancient origin of the word is the same, i.e. the carats used to measure precious materials.

Anello a fascia in oro 22 carati
Band ring in 22 carat gold

In the case of the karats that refer to gold, however, they indicate the thousandths of quantities of gold (or other precious metals) contained in an alloy. The maximum, as regards gold, is 24 karats. You will never find gold of 25 or more carats. The 24 karats indicate that the gold is 100% pure. The 24 karats are the basis for calculating the rest (always for gold). The 18-karat jewels, therefore, are 75% gold. It is calculated as follows: 18: 24 = 0.75. Similarly, a jewel with 14% gold means that it contains slightly more than half of gold, the rest are other metals (14: 24 = 0.58).

In some cases, the karats of gold can also be indicated with the number that refers to the percentage (the result of the arithmetic division). For example, 18-karat gold can also be indicated with the initials 750, 14-karat gold with 583 and so on. Again, if you read the number 375 in a jewel, know that it equals 9 karats.

The karats are also used for silver. The silver sterling, for example, contains 92.5% of silver and 7.5% of other metals, generally copper. It is generally referred to as 925 silver.

Anello Wave Stacking in oro 24 carati
Menē, Wave Stacking ring in 24 carat gold
Anello Bahia in oro 18 carati e diamanti
Bahia ring in 18K gold and diamonds
Anello in oro rosa 14 carati
14K rose gold ring
Anello in oro rosa 9 carati e diamante ice
Ring in 9 carat rose gold and ice diamond
Anello in argento satinato e lucido
Satin and polished 925 silver ring

What are laboratory diamonds?

It has been talked about for years, but many people still don’t have a clear idea of ​​what stones are called lab grown diamonds. If you are looking for a quick and concise description of artificially produced diamonds, here we are. Basically, there are two methods to produce man-made diamonds, but in both cases the gems are identical, from a chemical point of view, to natural stones. But the similarity ends there.

Synthesis diamond con taglio a pera
Synthesis diamond con taglio a pera, pietra creata in laboratorio

The name of the diamonds
But, first of all, what are these diamonds called? In English the definition lab grown is the most used, especially by the marketing of those who produce or sell these synthetic diamonds. The idea that diamonds grow in the laboratory like tomatoes in a greenhouse offers a greener view of the product. The communication of those who produce and sell them is based precisely on the idea that diamonds created in the laboratory (but in reality they are factories, as for any other product), are more sustainable. Right? Wrong? We see.
Diamante di laboratorio prodotto da Aether Diamonds
Diamante di laboratorio prodotto da Aether Diamonds

Sustainability
A natural diamond, created 2 or 3 billion years ago by the movement of the earth’s crust, is the result of the incredible pressure caused by the shifting of continents. Natural diamonds are therefore found under the ground. To be mined, diamonds must be searched deep or through large excavations in remote areas. Of course this activity, even if it is well controlled today, cannot be defined as sustainable. But, on the other hand, we must not forget that the extraction of natural diamonds also offers a livelihood for thousands of families in poor areas, such as Africa. Finally, any smartphone that you have in your pocket is the result of the extraction from the earth of a large number of minerals and no one is scandalized.
Un impianto di produzione di diamanti sintetici
Un impianto di produzione di diamanti sintetici

In any case, is it true that lab-created diamonds are green? It depends. First of all, man-made diamonds require an enormous amount of energy to be produced. The vast majority of these diamonds are produced in China and India, but also the United States and Israel, and in many countries, coal-fired plants still represent the predominant source of energy. The emissions caused by the production of lab grown diamonds cannot be considered completely green. Furthermore, few people are needed to produce synthetic diamonds and, therefore, their positive contribution to the social economy is very low.
Ricerca di gemme in miniera
Ricerca di gemme in miniera

How are they produced?
Diamonds that come out of a laboratory are produced using two very different methods: CVD (chemical vapor deposition) and HPHT (high pressure at high temperature). Currently the CVD system seems to prevail and, according to some, even offers a better result. So, if you want to buy a jewel with synthetic diamond, you can take the curiosity to ask what type of factory it was produced from. However, both methods use the same basic material: carbon.

The HPHT system
The HPHT process uses a metal catalyst to dissolve the carbon. This process has a disadvantage: a few tiny pieces of metal can enter the diamond and cause visible inclusions. The carbon used, in fact, is pressed inside a metal cube, exposed to immense heat and pressure through electrical impulses. In this way the carbon breaks down and crystallizes in a diamond. But tiny traces of metal inside could make the diamond attracted to a magnet. It sure wouldn’t be nice to buy a diamond ring and then hang it on the fridge door (we’re kidding).

Controllo del reattore al plasma CVD che produce diamanti ​​in laboratorio
Controllo del reattore al plasma CVD che produce diamanti ​​in laboratorio di De Beers

The CVD system
To produce a diamond with the CVD method, a tiny fragment of natural diamond is locked in a machine. Here it is exposed to carbon-rich gas and brought to extremely high temperatures. Within a few weeks, the carbon gas ionizes and the mineral particles stick to the original diamond and then crystallize.
Un diamante grezzo emerge dal reattore al plasma CVD
Un diamante grezzo emerge dal reattore al plasma CVD

Are laboratory diamonds the same as others?
From a chemical point of view, the diamonds produced in the laboratory are the same as those extracted in a mine. They are, therefore, like any mass-produced object. Natural diamonds, on the other hand, have an unpredictability of color, transparency and size that, obviously, is not present in synthetic diamonds.
Punto luce di Lightbox
Punto luce con diamante di laboratorio Lightbox

Are all synthetic diamonds the same?
No, as with natural ones, synthetic diamonds can also have a different quality. It is only recently, however, that the major institutes have begun to classify them. GIA and IGI, for example, judge them by cut, color and clarity, just like natural diamonds. Excellent cut, D to F color and VS2 to SI1 clarity are the best categories.
Diamante di laboratorio del peso di 2 carati, venduto da Lightbox per 1850 euro
Diamante di laboratorio del peso di 2 carati, venduto da Lightbox per 1850 euro

How much does a synthetic diamond cost?
The price of a lab-made diamond is determined by many factors. The first is the size, then from the famous 4 Cs that are used to classify all diamonds. Until recently diamond factories were unable to produce large gems, over one and two carats. It is now much more common and quite large diamonds have also been produced. The price, however, is much higher. In any case, lab grown diamonds cost less than natural ones. Over time, however, their price decreases, that of natural diamonds tends to increase.
Read also: https://gioiellis.com/it/il-futuro-dei-diamanti-di-laboratorio
Anello con diamanti di laboratorio
Anello con diamanti di laboratorio

Features
Laboratory diamonds are as hard and resistant as natural diamonds: they have a rating of 10, which is the highest, on the Mohs scale. Even on a jewel they shine exactly like the others. When buying a diamond jewel can you distinguish if it is natural or synthetic? No, even for a jeweler or gemologist it is impossible to distinguish a natural diamond from an artificial one. However, there are laboratories with special equipment that can identify a diamond created in the laboratory.

Orecchini lab-grown di Lightbox
Orecchini lab-grown di Lightbox







All about diamonds and carats




Why are diamonds measured in carats (as well as for transparency, cut and purity)? And why are the carats of diamonds different from the carats that are used for gold? Questions that are often addressed to the gioiellis.com editorial staff. If you do not know what is meant by carat about diamonds or gold, here is a quick explanation.

Anversa: acquisti di un buyer
Antwerp (Anversa): acquisti di un buyer

History. It all starts with beans. That’s right: the word carat, or carat, comes from the Arabic word qīrāṭ, which means bean pod. But also the ancient Greeks called beans and carobs with the name of keration. But what does a diamond have in common with beans? Simple: in ancient times the seeds, which were the size of most gems, were used to determine the weight of diamonds. But a couple of centuries ago it was decided to establish a common value (not all beans are the same, after all). One carat, for diamonds, has been set at a weight of 200 milligrams or, if you prefer, 0.2 grams. Thus, a 1-carat diamond weighs 0.20 grams (equivalent to 0.007 ounces), a 2-carat diamond weighs 0.4 grams, and so on. You will more easily find jewelry made up of diamonds weighing much less than 1 carat. For example, a 0.05-carat diamond ring, which is a fairly common size, has a stone that weighs 0.01 grams (equivalent to 0.0004 ounces). And there are also those who, like Tiffany, measure diamonds up to one thousandth of a carat.
Selezione dei diamanti nel laboratorio di Antwerp (Anversa)
Selezione dei diamanti nel laboratorio Tiffany di Antwerp (Anversa)

Shape and weight of diamonds. Carats are not everything: for the same weight, a diamond can appear more or less large according to the chosen cut, for example, brilliant (round), princess, oval, cushion, marquise, emerald, radiant or heart. In short, the carat weight does not indicate exactly the size. You may also read the abbreviation Tw: it is an abbreviation that is used for total weight, which is usually used to indicate the total weight of all the diamonds in a jewel.
Diamanti in vendita ad Anversa
Diamanti in vendita ad Anversa

The karat of gold. The word carat is also used for gold, but it indicates something completely different. For gold, the amount of karats measures the percentage of pure metal used: 24 karat gold means that 100% is pure gold. 18-karat gold indicates that 25% of the jewel is made up of other metals, such as silver, copper, palladium. A 14 karat gold ring is an alloy with 14 parts of gold and 10 parts of other metals. But why are there 24 karats of gold? The proportion dates back to the time of the ancient Romans at the time of the Emperor Constantine, who considered 24 silique, a silver coin, equal to a solid of gold, as the most valuable coin was called. For 1500 years, more or less, gold has therefore had two values: weight (in grams or ounces) and purity (carats).
Lingotti e monete d'oro
Lingotti e monete d’oro

Carat and Karat. In many languages ​​the word carat between diamond and gold is indistinguishable. In English, however, Carat is used for diamonds (and gems in general) and indicates the weight, while Karat is used for gold (abbreviated Kts). Thus it is much more precise and there is no confusion.

Diamante ovale impeccabile D Color da 102,39 carati
Diamante ovale impeccabile D Color da 102,39 carati







How to distinguish cubic zirconia from zircon

Do you know the difference between zirconia and cubic zirconia? They are two completely different minerals (even in price). This is what zircons and cubic zirconia are and why it is important to know the characteristics in order not to fall into the trap

Synthetic diamonds or zircons? What if, on the other hand, they are cubic zirconia? Almost always the description of the jewels proposed by the manufacturers indicates which type of stone is used on rings, necklaces or bracelets. But this description is not always true. From your emails, in fact, we discovered that few really know the difference between zircons (a natural stone) and cubic zirconia (a synthetic crystal). The problem is that companies often offer jewelry with “zircons”. But in reality it is not about zircons, but cubic zirconia. And there is a big difference (even in the price): cubic zirconia cost very little. Better to clarify your ideas, then.

Anello in oro bianco con zircone blu da 12,62 carati circondato da 153 diamanti
White gold ring with genuine 12.62 carat blue zircon surrounded by 153 diamonds

Cubic zirconia. It is one of the more popular alternatives for a diamond. For chemistry it is zirconium oxide, and it is often used as a synthetic diamond. If you read the initials Cz in the description of a jewel, it is cubic zirconia. It is a crystal, on the market since 1970. The physical properties are very similar to those of a diamond, so much so that it is difficult to distinguish them with the naked eye. Most cubic zirconia is colorless, but there are also colored ones. One aspect that distinguishes it from a real diamond is its thermal conductivity: like real zircon, cubic zirconia tends to be a thermal insulator compared to diamonds, which are heat conductors.

Anello in argento con zirconia cubica bianca
Pandora White Cubic Zirconia Silver Ring

Zircon (zirconium silicate). It is a natural gem, and closely resembles a diamond. Among the characteristics that make it very similar to a diamond is the refraction capacity, even if the zircon is more opaque. Otherwise, zircon is quite similar to a diamond. It is an often colorless stone but, like real diamonds, it can have colored shades: green, pink, purple, white, yellow and blue, which is the most requested color. Although the colors of the zircon are natural, the stones can also be heat treated to make the gem colorless or, conversely, to increase the hue. The major visual difference of a zircon compared to a diamond is that the reflection of light is different, less brilliant.

Diamonds: are better originals or fake?

Anello zon zircone malese e ceramica
Doris Hangartner, ring with real Malaysian zircon and ceramic
Orecchini in argento con cubic zirconia
Silver earrings with cubic zirconia by Rosato
Anello in argento con cubic zirconia
Silver ring with cubic zirconia by Michael Kors
Uno grande zircone grezzo
Un gros zircon brut

What is the difference between yellow gold and white gold?




What is the difference between yellow gold and white gold? Obviously, the color. But you want to know more. It’s a good idea, because there are a lot of differences between yellow gold and white gold. And even the valuation, in case you want to sell a jewel, can vary, both for yellow gold and for white gold. So, besides the color, what are the differences between yellow gold and white gold? And does white gold cause allergies?

Anello chevalier in oro bianco
Anello chevalier in oro bianco di Schreiber

Let’s start with a fact: the gold that is extracted in the mines or in the straws found in the sand of some rivers is yellow. In nature there is no white gold, which is a human invention. White gold is produced by combining yellow gold with other metals. But, let’s open a parenthesis: almost all yellow gold jewels are also alloyed with other elements. Gold in nature is 24 carat, but it is also very malleable. 24-karat gold jewelry is easily deformed and is used only by very few jewelers, especially in countries such as India. In general, however, gold is used for jewelry that is melted with other metals, such as copper or silver, which make it more solid.

Spilla in oro giallo e bianco con diamanti e perla barocca al centro
Spilla in oro giallo e bianco con diamanti e perla barocca al centro by Buccellati

How much pure gold is there in a jewel? The answer is easy: the carats indicate it. For example, an 18-karat gold ring will have 750 parts of pure gold and 250 parts of other metals. Or, a jewelry with 14 karat gold will have 585 parts of gold and 415 parts of other metals. And with 9 carats the percentage of pure gold drops to 375 parts or, if you prefer, it is 37.5%. Of course, with less carats of gold the value will also be lower.

Anello in in oro 24 carati martellato
Anello in in oro 24 carati martellato

And what about white gold? The same concept applies to white gold as well. But, unlike yellow gold, it is melted together with white metals, to form an alloy that makes it lose all or almost the yellow color. In short, it is a purely aesthetic choice. Although, in truth, up until a few decades ago white gold was not so popular. In the last century, those who wanted a ring with white metal often chose a platinum jewel. A metal that, however, is also more difficult to work and rarer (as well as more expensive).

Bracciale in oro bianco, diamanti e zaffiro blu
Bracciale in oro bianco, diamanti e zaffiro blu by Gismondi 1754

White gold has become very popular, and is used, in particular, for engagement rings. But, as we wrote at the beginning, not all white gold is the same. To be precise, there are white gold jewels made with at least fifteen different alloys. The main white gold alloys are obtained by adding nickel, in different percentages, or palladium and silver, but also copper and zinc. To these we must add rhodium, a metal that is very often used as an external patina, to make the jewel more shiny and whiter. Over the years, or due to a few scratches, this patina can be damaged. But just take it to a jeweler to make the jewel rhodium again.

Anello in oro bianco rodiato e diamanti della collezione Milano di Pomellato
Anello in oro bianco rodiato e diamanti della collezione Milano di Pomellato

Does white gold cause allergies? It is very difficult for gold to cause a skin allergy. But it is not uncommon for the metals contained in an alloy with gold to cause some skin reactions. This happens more easily with jewelry that has a low percentage of gold, essentially those with a lower carat.

Anello trilogy in oro bianco e diamanti
Anello trilogy in oro bianco e diamanti

Is a white gold jewel worth less than a yellow gold one? The answer is no. The value of a jewel can be determined by the shape (for example, if it is of a famous brand), by the stones with which it is composed, for example diamonds or precious gems, and by the percentage of gold contained in the metal. That is, from karat gold: an 18-karat white gold jewel contains the same amount of gold as an 18-karat yellow gold jewel.

Bracciale Love in oro bianco e 10 diamanti
Bracciale Love in oro bianco e 10 diamanti di Cartier

For which types of jewelry is white gold recommended? The answer is easy: for everyone. But, in particular, white gold makes diamonds stand out, as long as the stones have an excellent color, essentially they are classified from D to G. A diamond with a color from H to K or L (i.e. with a very slight tendency to yellow or gray) will probably stand out more on yellow gold: it will appear whiter. But the more colored diamonds, from the Light Yellow classification onwards, will once again be appreciated better on white gold.

Anello Atlas X in oro bianco con diamante di Tiffany
Anello Atlas X in oro bianco con diamante di Tiffany

Fedi in oro bianco e giallo
Fedi in oro bianco e giallo di Niessing