Black diamond

Black diamond is an intriguing name, isn't it? It is one of the most unusual gemstones that will definitely not leave you indifferent! It is a matte crystal that acquires its color due to particles of graphite, metals and other impurities. It looks very mesmerizing, attracts people's eyes with its spectacularity. Black diamonds were first found in Brazil, then later in Africa. Scientists believe that they appeared almost 4 billion years earlier than colorless ones. Where did such unusual diamonds come from? There are only two theories of their origin: the first says that black diamonds came to Earth together with falling meteorites, the second - that they appeared on the surface during volcanic eruptions. Indeed, these diamonds are located not deep in the bowels of the earth, but much closer than the same colorless diamonds. Fig. Black diamond Accessories with a black diamond are suitable both for evening events and for wearing in everyday life, will add zest to the image…
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A champagne-colored cognac diamond.

If until now you imagined a diamond as a colorless stone, keep in mind that it can also be colored. And some of the most popular now are the marvelously beautiful brown-colored diamonds called Coqnac. Look closely at such a champagne-colored diamond, and you will think that you are looking at a champagne glass with sunlight penetrating through its honey-colored thickness. Turn the stone sideways and a new and stunning hue will appear inside the stone. The brown color of diamonds was obtained due to iron and nickel, the amount of inclusions of which in the crystal lattice of the stone determines the saturation of the shade. There is another category of cognac diamonds, called cape, which has nitrogen atoms in its structure. When crystallized, they give the stone a brown color. These minerals are considered lower quality because nitrogen reduces the transparency and density of the diamond. Figure 1. Cognac diamonds Champagne-colored diamonds were first discovered at an Aust…
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Yellow diamond

At the mention of diamonds, we most often imagine the classics - colorless round-cut stones. In fact, everything is more interesting: there are not only different shapes of diamonds, but also many fancy colors, which are not inferior in attractiveness to the usual variants. An example is yellow diamonds. They are not as rare as, for example, pink or blue ones, but they are much less numerous than colorless ones.

Fig. 1. Earrings and rings with a yellow diamond

The yellow color in stones arises due to the nitrogen content: the more intensively the carbon from which the diamond is formed absorbs nitrogen, the more pronounced the hue becomes. The other properties of yellow diamonds are the same as those of colorless diamonds. They are just as strong and reflect light rays.

And if, for example, black diamonds do not have a clarity rating (it's simple - you can see nothing in them anyway), yellow …

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Shapes of diamond cuts

As the name suggests, the shape of the cut (round, princess, radiant, etc.) describes the shape of the diamond, primarily the top view. All cut shapes have their own parameters and characteristics, but in general, the beauty of a diamond's shape is a matter of individual taste. The brilliance and play of a diamond depend on the quality of polishing and cutting, the shape and proportions of the stone. All of these are components of the final value of a cut gemstone. A round brilliant with 57 facets can be considered a classic diamond. This shape allows the stone to reflect the vast majority of light. In addition, a stone of this shape can boast a truly magnificent play. Not surprisingly, diamonds of this shape are more common than others and are very expensive. Fig. of different cut shapes But the round shape is not the only shape for diamonds. There are many different cut shapes in the world. The so-called "fancy" shapes are very popular. Each of them, be it "marquis",…
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How to tell the difference between a moissanite and a diamond.

The mysterious moissanite is called the "little brother" of the diamond. What is this stone, how to distinguish mouassanite from a diamond and which of the variants of inserts to prefer - we will deal with in our article. Moissanite - what is it Moissanite - silicon carbide (carborundum), which was discovered in 1893 by the Frenchman Henri Moissan and was named after the scientist. Natural moissanite is rare on Earth: it can be found in corundum deposits, kimberlite rock and some meteorites. The rarity of moissanite is due to the fact that its formation requires extremely high temperature and high pressure, which coincide these two factors in Earth conditions very rarely. Due to its rarity and small size, natural moissanite has no jewelry value. But seeing the potential in this stone scientists created an artificial one. Its production began in the late 80s of the XX century, and since the 90s artificial moissanite has been used in the jewelry industry. It is even called an ana…
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Weight to diameter ratio

Approximate ratio of the diameter of a diamond cut in the Kr-57 cut ("Circle") to its weight. Cut of the diamond (number of diamonds in 1 carat) Diameter of diamond, mm Diamond weight, carat 400-200 0.90-1.10 0.002-0.005 200-120 1,15-1,25 0.005-0.008 120-90 1,30-1,43 0.008-0.011 90-60 1.45-1.64 0.011-0.0166 60-40 1.65-1.88 0.0166-0.025 40-30 1.89-2.05 0.025-0.033 30-25 2.10-2.20 0.033-0.039 25-20 2.21-2.36 0.04-0.05 20-15 2.40-2.60 0.05-0.07 15-10 2.66-2,95 0.07-0.10 10-7 3.00-3.30 0.10-0.14 7-6 3.35-3.55 0.14-0.17 6-5 3.60-3.75 0.17-0.20 5-4 3.80-4.05 0.20-0.25 4-3.4 4.10-4.30 0.25-0.299 0.30-0.39 4.35-4.70 0.30-0.39 0.40-0.49 4.75-5.10 0.40-0.49 0.50-0.59 5.15-5.40 0.50-0.59 0.60-0.69 5.45-5.70 0.60-0.69 0.70-0.79 5.75-5.95 0.70-0.79 0.80-0.89 6.00-6.20 0.80-0.89 0.90-0.99 6.25-6.40 0.90-0.99 1.00-1.24 6.45-6.90 1.00-1.24 1.25-1.49 6.95-7.35 1.25-1.49
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Hearts and arrows

The quality of a diamond cut is directly dependent on a variety of parameters. Currently, there are several systems for determining the quality of a gemstone.

The most widely used system was developed by the Gemological Institute of America (GIA).

In ascending order of diamond quality, all stones are divided into five grades: poor, fair, good, very good and excellent.

According to the Russian system, diamonds are categorized into A, B and C: excellent, good and fair quality respectively.

The list of systems does not end here. Thus, the American Gemological Society (AGS) has created a more detailed system that includes in the evaluation process such parameters as proportions, polish quality and symmetry. Each of the parameters corresponds to a scale from 0 to 10, where a mark of "0" indicates perfect quality and "10" indicates very poor quality.

For example, a perfect diamond would be label…

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