Carat weight

What's the weight of the diamond?

The weight of diamond is the most easily measured feature in 4c. Like other precious stones, the weight of diamonds is calculated in carats. The word "carat" comes from a seed called "small horn tree". Because the weight of this seed is surprisingly consistent, it was used to weigh diamonds in the early days. One carat is equivalent to the weight of a small horn tree seed. The current standard is that one carat equals 0.2g, and each carat is divided into 100, so a 25-cent diamond weighs 0.25 carat. Diamonds of the same quality, the greater the weight, the more precious.

Why is the price of 1 carat more expensive than that of 99 cents?

The influence of carat weight on diamond price is not a simple linear relationship. Usually the price of diamonds per carat is given. Other elements being the same, the heavier the carat, the higher the price. However, some "ideal" weights will lead to a sudden increase in prices. These wonderful weights are 0.5ct, 1ct, 2ct, 3ct and so on. The price per carat of a diamond weighing 0.95 carats is lower than that of a diamond weighing 1.0 1ct of the same grade. The same principle applies to 1/4ct and half-carat diamonds.

Color (color)

How many colors can diamonds be divided into?

In an ideal state, diamond is completely equiaxed, and has no selective absorption in the visible range, so it is colorless. However, naturally occurring colorless and pure diamonds are extremely rare, and most diamonds are destroyed by the external growth environment during their long growth process, resulting in different shades of colors.

Generally speaking, the colors of diamonds can be divided into three categories:

1. Cape series: including colorless, light yellow and yellow diamonds;

2. Brown series: including brown and gray diamonds with different intensities;

Color series: including pink, purple, gold, blue and green diamonds.

What is the regulation of diamond color grade?

Colored diamond in diamonds has an independent evaluation system. For colorless series of diamonds, from low to high, the hue concentration starts from D color and gradually decreases to Z color. D-colored diamonds are completely colorless and transparent, which are very rare in nature and have high value. Z-colored diamonds have high color concentration, which can be used as a boundary to distinguish colored diamonds. In other words, if the hue saturation of a diamond is higher than that of a Z-colored diamond, it should be classified as colored diamond.

Why is the top grade diamond not A color, but D color?

If the highest grade of a diamond is a color, then in order to show that your diamond is better and whiter than a color, it is easy for individual businesses to have irregular color grade evaluations such as double A, triple A and A+. This is not good for the color grading of the whole diamond. Moreover, the first letter of the English word for diamond is D, so the international community defines the diamond with the highest color level as D color, and terms such as D++ are out of the question, thus avoiding the occurrence of the former situation.

How to identify the color grade of diamonds?

Most gem-grade diamonds belong to Cape series, namely colorless-light yellow series. When identifying the color of diamonds, the identified diamonds are compared with a set of international standard colorimetric stones, and the colors of the standard colorimetric stones are arranged from colorless D (the highest grade) to yellow Z in turn. ..

Are diamonds fluorescent?

About 50% of diamonds emit visible light under the irradiation of ultraviolet light, which is called ultraviolet fluorescence. Some people look for diamonds that can produce this unique effect, while others avoid buying them. Different fluorescence levels can only be distinguished by professionally trained jewelry appraisers.

Does the fluorescence of diamonds affect the color of diamonds?

The fluorescence of diamond will have a great influence on the color of diamond. Especially when life is full of ultraviolet rays, the ultraviolet fluorescence of diamonds can not be ignored. The diamond lamp needed for diamond color grading does not contain ultraviolet rays, which can eliminate the influence of ultraviolet fluorescence on diamond color and determine the color grade of diamond well. There are four levels of fluorescence intensity: strong, medium, weak and none. If a diamond has yellow hue and blue fluorescence, it will appear white in daily light. Too much fluorescence will make the diamond surface look blurred.

Clarity (clarity)

What determines the clarity of a diamond?

The clarity of a diamond refers to the number of inclusions in the diamond, and also indicates the surface defects in the diamond to a lesser extent.

The purity of diamond represents the cleanliness and transparency of diamond, which is mainly determined by the quantity, size, position, brightness and type of inclusions. Diamonds are rarely perfect, and these five factors are equally important to every diamond, whether it is a small diamond or a big diamond. Obviously, large diamonds with high clarity are rare, and their carat price is higher than that of smaller diamonds with the same clarity grade.

How to classify the grade of diamond clarity?

Gemological Institute of the United States will use a magnifying glass with a magnification of 10 when inspecting diamonds, and identify the 1 1 grade of diamond clarity according to GIA standards. Starting from Flawless (FL), that is to say, there are no flaws in the interior and surface of the diamond, and then proceeding to the lowest flaw level (I3), it is described that inclusions and flaws in the stone can be found only by naked eyes.

FL is flawless. Observe that the diamond is clean under the magnifying glass of 10 times the gem, that is, there are no inclusions inside and outside the gem.

If the diamond is flawless, then the diamond under the 10 times gem magnifying glass is flawless, but there may be some flaws on the surface, which can be removed by grinding again.

VVS has a very slight defect. Observing the diamond under 10 times gem magnifying glass, we can see that there are very small flaws in the pavilion or surface. The difference between VVS 1 and VVS2 is that the latter has small cotton spots and stubble.

When you look at the diamond under the 10 times gem magnifying glass, you can see very tiny flaws. The difference between VS 1 and VS2 is that the latter may have tiny cotton spots or cotton stubbles.

SI micro-flaw: it is easy to see the flaw when observing the diamond under the 10 times gem magnifying glass, and it is extremely difficult for the naked eye to detect it.

I defects I 1, I2, I3 refer to small defects that can be easily seen by naked eyes, and some of them have obvious cleavage and cracks.

It is worth noting that all diamonds are observed with a magnifying glass of 10 times, and only Grade I can easily see the defects with the naked eye.

What is the effect of diamond clarity on diamond value?

Because diamond is a substance formed by the long natural action of the mantle, it will inevitably enter some tiny impurities and growth lines during the crystallization process. These marks are the natural growth marks of diamonds. Among the naturally produced diamonds, completely clean diamonds are very rare. Most of the original diamonds mined can only be used as industrial diamonds, which can't reach the gem level. Therefore, the higher the clarity, the rarer the diamond and the higher its value.

Cut (cut)

What is the status of diamond cutting in 4C?

In the 4c standard of diamond value measurement, only cutting is directly affected by human activities. Although diamonds can be processed into different shapes (fancy) to meet different tastes, the fineness of cutting directly affects the fire and sparkle of diamonds. Rough diamonds have no luster. Only through the precise design and ingenious carving of well-trained masters can diamonds be unveiled, so that they can make full use of the nature of light and present a rainbow-like "fire color" with flashing characteristics.

What are the main styles of diamond cutting?

At present, the most common cutting and grinding method in the market is round bright cutting, which is usually called standard round drill. At present, diamond rings and other diamond ornaments seen in shopping malls are mostly cut in this way. In addition, we often see some styles, such as emerald, princess square, pear shape, heart shape, olive shape and so on.

Why are standard round drills on the market so popular?

This should be considered from several aspects.

First of all, the circle is the most reasonable, gentlest and most acceptable shape, and it is aesthetically optimal, and it will not be as angular and too sharp as a square;

Secondly, the circle is the easiest to inlay, the most symmetrical and the most stable;

Thirdly, in the process of diamond processing from rough to finished diamond, the yield of finished diamond is very critical, and the weight of finished diamond almost directly determines the final price. Most of the original diamonds are octahedral in shape. After calculation, an octahedral diamond crystal is processed into two round diamonds, one large and one small, and the total yield is the highest. So diamonds are often processed into round diamonds;

Fourthly, as one of the most classic styles, the design of angle and proportion can best reflect the luster and fire color of diamonds, that is, the beauty of diamonds. This point has been tested by long-term practice. Other cuts are mostly used in colored diamond, and the requirements for fire colors are not so high. The focus is on the expression of body color. Natural colored diamonds are very rare.