Describe the dimensions of the jewellery you imagine in centimetres or millimetres. This will help us calculate the approximate weight of gold needed for its manufacture.
In the table, we have presented the inner diameter of each ring size and the corresponding European size (the size number corresponds to the inner circumference of the ring). For us, the only accurate method to determine the correct size is the use of jewellery measurements. All other methods we have tried result in minimal to significant deviations.
If you have a ring that fits, measure its inner diameter with a caliper.
*For orders we have already taken, we can provide and send jeweller’s measurements for you to take an accurate measurement.
If you have any questions, feel free to contact us for assistance.
| Diameter (mm) | EU |
|---|---|
| 14.3 | 45 |
| 14.7 | 46 |
| 15.0 | 47 |
| 15.3 | 48 |
| 15.6 | 48 |
| 16.0 | 50 |
| 16.3 | 51 |
| 16.6 | 52 |
| 17 | 53 |
| 17.2 | 54 |
| 17.5 | 55 |
| 17.8 | 56 |
| 18.1 | 57 |
| 18.4 | 58 |
| 18.8 | 59 |
| 19.1 | 60 |
| 19.4 | 61 |
| 19.7 | 62 |
| 20 | 63 |
| 20.4 | 64 |
| 20.7 | 65 |
| 21 | 66 |
| 21.3 | 67 |
| 21.7 | 68 |
| 22 | 69 |
Choosing a bracelet length is important, as most bracelets are difficult to shorten and lengthen. Below, we have outlined the recommended steps to help you determine the right length for your wrist.
If you have a bracelet that fits perfectly, measure its length including the clasp.
* Note that there may be a slight difference between your left and right wrist.
The choice of necklace length may depend on the characteristics of your body and the features of the jewellery. As a guide, we have graphically depicted the standard lengths of chains to help you visualize your options.
In this article we will look at what types of diamonds exist and what their main characteristics are. You will also be able to learn about the types of synthetic diamonds and which type of diamond they most commonly fall into.
It is a curious fact that colorless natural diamonds most often fall into one type, while colorless synthetic diamonds mostly fall into another type. Because of the differences in characteristics of the two types of diamonds, they can be identified from each other using ultraviolet light. It is this type of test that we will discuss in more detail in this article as a method of indicating whether a diamond is natural or created in a laboratory. If you are unfamiliar with what fluorescence and phosphorescence are in gemstones we advise you to first read our article dedicated specifically to this.
This article is intended for advanced readers who want to learn a little more about diamonds, and how to distinguish natural from synthetic diamonds through their fluorescence and phosphorescence. If you haven't yet read our article on how to determine the quality of a diamond or just want a lighter read then we recommend you start with it.
Diamonds are divided into two main types - Type I and Type II with each being further divided into A and B. Therefore, there are diamonds that can belong to Type Ia, Type Ib, Type IIa or Type IIb. Each has its own specific characteristics, which we will summarise very briefly in the lines below.
Diamonds of this type are characterised by the nitrogen content of their structure. They are further subdivided into Type Ia and Type Ib. Nitrogen in Ia diamonds occurs in pairs or groups of atoms. On the other hand, the nitrogen in Type Ib diamonds is distributed in the diamond crystal as single atoms and is not concentrated in masses.
Natural Type Ia diamonds are the most common in nature. In contrast, Type Ib are rarely found in nature. Both Ia and Ib are characterized by a lack of electrical conductivity and very good thermal conductivity.
Typical Type Ia diamonds range from colorless to yellowish, yellow, brown, olive green, gray, or green (rare). Type Ib diamonds are "fancy yellow," more deeply yellow than Type Ia.
They are characterized by not containing significant amounts of nitrogen. In the 1950s, scientists further divided them into two subtypes, Type IIa and Type IIb.
Natural Type IIa diamonds are very rare in nature, while Type IIb diamonds are extremely rare in nature. Most natural blue diamonds are Type IIb.
Type IIa are not electrically conductive, but Type IIb are semiconducting. The thermal conductivity of Type IIa is 3 to 5 times that of Type I. On the other hand, the thermal conductivity of Type IIb varies from stone to stone.
Type IIa diamonds may be colorless, brown to light brown, sometimes pink or blue-green. Type IIb are most often blue, sometimes gray.
There are two main types of synthetic diamonds on the market - HPHT (high pressure high temperature) and CVD (chemical vapor deposition). Synthetic diamonds were first produced in the 1950s for industrial purposes. Around the year 2000, limited quantities of synthetic diamonds also appeared in jewellery. Nowadays, they are widespread throughout the world.
Unlike cultured pearls, which are grown in oysters or shells in nature and take from several months to several years to form, synthetic diamonds are produced in the laboratory in a relatively short time by scientists. This is one of the main reasons why cultured pearls are viewed positively in jewelry while synthetic diamonds are generally undesirable and avoided in high-end jewelry.
About 97% of all natural diamonds are Type Ia and about 1-2% are Type IIa. Less than 1% of all natural diamonds are Type Ib.
But most HPHT colored synthetic diamonds are Type Ib and most CVD and HPHT colorless diamonds are Type IIa.
The approximate prevalence of diamonds of each type is summarized in the following table:
When several diamonds are of the same type it is more difficult to distinguish a synthetic diamond from a natural one.
Because natural diamonds have formed deep in the earth over millions of years, they have a different growth pattern than synthetic diamonds produced in a lab over a period of days or weeks.
Distinguishing between a natural and synthetic diamond can be difficult and requires the evaluation of a certified lab to be sure. However, in this article we will discuss fluorescence and phosphorescence in diamonds in more detail. A relatively high percentage of natural and synthetic diamonds can be identified from each other using this type of testing. This is due to the fact that colorless natural diamonds are mainly Type Ia, and synthetic colorless diamonds are mainly Type IIa. While one emits a stronger light when illuminated with long-wave ultraviolet light (LW UV) compared to short-wave ultraviolet light (SW UV) in the other it is the other way around. The color of fluorescence is also usually different in natural and synthetic diamonds.
If you are not familiar with what fluorescence and phosphorescence is in gemstones we advise you to first read our article dedicated specifically to this before moving forward.
Below we have summarized the main characteristics of Type I and Type II diamonds:
Natural diamonds typically fluoresce more strongly in LW UV light compared to their fluorescence in SW UV light.
Blue is the most common color in LW UV fluorescence in colorless and yellow natural diamonds.
The fluorescence in HPHT yellow and colorless synthetic diamond varies from none to greenish-yellow to grayish-yellow. In some cases, it is possible to observe pale bluish-white fluorescent colors in HPTH synthetic diamond.
CVD synthetic diamond typically fluoresces in orange to orange-yellow colors. After HPHT treatment, it fluoresces yellow-green under SW and LW UV light.
A yellow, colorless or nearly colorless diamond with strong blue fluorescence under LW UV light is very likely natural.
Generally, the distribution of UV fluorescence on a natural diamond is more uniform than on synthetic specimens.
When evaluating the fluorescence of a diamond, it is best to place the stone on a black surface and perform the test in a completely dark room. Allow your eyes to adjust to the darkness and be sure to wear protective eyewear.
Although fluorescence is a good indicator, you should not rely on a single test to identify natural and synthetic diamonds. To be absolutely sure, you need to go to a certified laboratory or a specialist gemologist with the necessary equipment and skills.
If the visible light emitted by the gemstone continues after the initial source of ultraviolet rays has stopped then it means that the stone is phosphorescent.
Below we have summarized the main characteristics of Type I and Type II diamonds:
Synthetic colorless and blue diamonds usually phosphoresce longer under SW UV light than natural diamonds once the light is turned off.
In fact, some synthetic diamonds can phosphoresce for several minutes to several hours in the dark.
In comparison, the phosphorescence of natural blue diamonds is typically less than 30 seconds, although exceptions occur here as well, such as Cullinan diamonds.
In this article, we looked at Type I and Type II diamonds and their basic characteristics. We introduced you to the curious fact that about 97% of all natural diamonds fall into Type Ia and about 1-2% are Type IIa. In contrast, most CVD and HPHT colorless diamonds are Type IIa.
Because of the differences in the characteristics of the two types, they can be distinguished from each other using ultraviolet light. While one emits a stronger light when illuminated with long-wave ultraviolet light (LW UV) compared to short-wave ultraviolet light (SW UV) in the other it is the other way around. Fluorescence color is also usually different in natural and synthetic diamonds.
Of course, one should not rely on a single test to identify natural and synthetic stones. This should only serve you as an initial indicator. To be sure you need to go to a certified laboratory or to a specialist gemologist with the necessary equipment and skills.
If the exciting moment to propose to your better half is approaching in our blog we have prepared a special article about it how to choose the perfect engagement ring, and you can also learn how to determine the quality of a diamond and learn about the process of ordering a diamond engagement ring in our page prepared especially for this. There you can also view some of the pieces we have made for our clients.
Our consulting gemologist is always available for consultation. You can contact us via the contact form, Facebook, Instagram or our phone number (+359) 898 241940.
