(diamond, diamond) 金刚钻, 金刚石
(diamond) (已 加工 的) 金刚石, 钻石
(diamond) (已 加工 的) 金刚石, 鑽石
金刚石, 钻石, 或 brill "yant
金刚石, 钻石, 或 brill "yant
(diamond) 钻石, 金刚石
(diamond) [阳] 钻石 金刚石
(diamond) 金刚石, 钻石
(diamond) 钻石, 金刚石
(diamond) 金钢 钻, 钻石
(染料 冠词), 金刚钻, 金刚石
[矿] κ, 多角形 钻石
金刚石, 钻石, 玻璃刀
琢磨 的 金刚石
(as well as outdated diamond)
1) Precious stone - a diamond cut and polished in a special way.
2) That, with the brilliance and play of light, resembles such a precious stone.
3) Decoration with such a gem.
The smallest of the typographic fonts (in the printing industry).
Refining is an artificial change in the appearance or properties of a precious stone (except for cutting) in order to improve its consumer properties. The most common methods of diamond refinement are irradiation, heat treatment, coating, filling cracks, drilling holes with a laser to "burn out" or dissolve the inclusion.
A diamond that has only been cut and (or) refined is not considered refined.
Scientists have learned to interfere with the structure of the stone, thereby improving its performance. With the help of modern technologies, it has become possible not only to destroy inclusions, but also to change the color of diamonds.
The world-renowned expert on precious stones, Swiss scientist, Professor Eduard Güble, on the issue of mineral refinement, expressed the following opinion: “Personally, I see no reason why we should not improve the quality (that is, color and purity) of natural minerals. We can say that nature has not finished the job of creating the perfect color and clarity. "
Of course, such a stone has improved characteristics, but it cannot be sold under the guise and at the price of a stone with the same natural characteristics, according to leading gemologists from different countries.
Refined diamonds are truly natural stones, mined in the same mines as other diamonds.
It is very important to know if the characteristics of the diamond you are purchasing have been improved. This is why it is customary to accompany all refined diamonds with the official "Natural Refined Diamond" gemological certificate, confirming that the given stone has been processed to improve clarity or color. The certificate is always marked treated (processed, refined)
1. IMPROVING THE PURITY OF THE DIAMOND
Laser drilling and crack filling
In 1982 in Israel, scientists invented a way to improve the clarity of diamonds. This revolutionary process makes the inclusions present in most diamonds invisible. The result is a visually cleaner and more sparkling diamond, the cost of which is 30-70% lower than the cost of a similar unrefined diamond.
The effects of improved purity are invisible to the naked eye; only a trained jeweler or gemologist can detect them.
Most diamonds have various natural inclusions. Even if they are faintly visible, they still tend to scatter light and reduce the brilliance of the diamond.
Technically, the cleanliness improvement process works like this:
To get to the switch, a laser drill is used to drill a tiny hole deep in the diamond. Often the high temperature of the laser will vaporize the speck. Otherwise, acid is poured into the hole, which dissolves the stain or whitens it.
Then, the resulting void is filled with a microscopic amount of material having the same optical properties as diamond. That is, the light passing through the pad and the main facets of the top is completely reflected from the facets of the bottom of the diamond, and exits through the main facets of the top and the pad, providing maximum brilliance and "play" of the diamond. The inclusion prevented the passage of light through the diamond, scattered it, and the stone seemed not clean enough to us.
After the process of improving the clarity of the diamond, the light passes through the processed natural inclusion, because the material used has the same optical properties as the diamond. The effect of this treatment can be very impressive, transforming even a nondescript diamond into a wonderful sparkling diamond. Such stones are sometimes referred to as "crack-filled diamonds". This technique is a lot like cracking a car's windshield.
The amount of filling material is so small that even the world's leading gemological laboratory GIA confirms that the process of improving the clarity does not add ANY WEIGHT to the diamond. The change in clarity of a diamond is considered permanent, and by the GIA. issues certificates for laser cut diamonds.
The holes are so small in diameter that it is very difficult to see that the diamond has been drilled. However, if you look at the stone in very bright light and 10x magnification, you can sometimes see a thin pink-lilac "thread".
Based on the definition of the clarity of a diamond, it can be improved by no more than 1-2 levels. The stones to be laser treated are located between the levels VS2 and I3, which have visible opaque inclusions. The processing trail should not be allowed to be more noticeable than the natural inclusion. Not every diamond can be improved, as not every inclusion can be removed.
All other things being equal, a clarity-enhanced diamond costs less than an unrefined diamond of the same clarity level, which saves approximately 30-70% or 30-70% more. If a diamond weighing one carat is purchased, then a refined stone with this weight will cost approximately 30-70% less than an unrefined one.
It is important to know the following:
1. Over time, refined diamonds do not lose their qualities. Manufacturer as a rule. gives a lifetime warranty on refined diamonds. The GIA confirms that it is eligible to provide a lifetime warranty for refined diamonds.
2. Ultrasonic or steam cleaning, sunlight and high temperatures will not harm the clarity-enhanced diamonds at all. But they cannot be dipped in acid, heated over an open fire, cut and polished again.
NEW "BLACK TECHNOLOGIES"
Now on the world market there are about half a million (according to approximate, and I think - very underestimated) carats of natural diamonds with an apparent clarity of I - SI, less often VS. Very good color, usually H and higher.
These stones were made in a laboratory previously located in Tokyo, and a few years ago transferred to Taipei. Several companies selling products made from such stones were based in Tokyo. The sale of loose stones was completely stopped in 2004 after the fact of their existence was discovered during the re-examination of a 3-carat diamond, which already had a GIA certificate. Even GIA experts have managed to certify more than 300 of these diamonds weighing 1 carat and above. All certificates for stones that fell under suspicion were revoked.
These stones were made from rough diamonds that had a good color, but the structure of the inclusions did not even fall into the category of technical ones. This unique technology, if not used for large-scale fraud, would be worthy of the Nobel Prize .. Developed by a brilliant chemical engineer, in Tokyo. You can distinguish such a diamond from a similar rough one. But if a diamond is in a piece, it is not that impossible, but extremely difficult.
The essence of the matter is that the stones are first cut and then laser cleaned. The voids created by the laser are filled with molten glass developed by this great Japanese chemist. (I would like to know his name) The glass mass is made on the basis of carbon with minimal impurities of some other elements, the absorption spectra of which are very close to the absorption spectra of the elements that make up gold.
This molten glass is unique not only in that its optical characteristics are practically indistinguishable from the optical characteristics of a diamond. This glass mass was the first synthetic material with similar optical characteristics and a DENSITY NOT EXCEEDING THE DENSITY OF DIAMOND. A stone filled with such molten glass, often 10-30% of the total volume of the stone, does not differ optically from a diamond. The same hardness, the same chemical resistance.
The fake was discovered by accident. One little-known gemologist from Los Angeles, not even outstanding at all, nevertheless discovered a strange thing. The certificate for the product indicated the exact data on the weight of the gold alloy and the weight of the diamond itself. According to the certificate, the stone passed as a diamond with perfect proportions. For such stones, gemologists have scoring tables. That is, a certain weight corresponds to one size or another. Fluctuations can naturally occur, but within 2-3%. And the stone on his table was 8.5% lighter than it should have been. That is, given its size and proportions, it had to weigh 3.24 - 3.26 carats, but weighed only 3.01.
A gemologist is a kind of universal scientist. He is a chemist, a geologist, a crystal scientist, a geochemist, and a geophysicist. Gemologists do not believe in miracles. Our hero received permission from the owners to dismantle the stone from the product, after which he conducted an elementary experiment - he determined the density of the stone. The density turned out to be the same 8.5% lower than a diamond should have. That is, the density of the molten glass turned out to be significantly lower than the density of a diamond, while possessing good fluidity, which is important for filling all even the smallest voids in the stone. And with a large volume of filling, this significantly affected the weight of the stone. The further process of solving the riddle was already a matter of technique, the secret was revealed.
If stones that have undergone a serious but officially recognized refining procedure lose in price from 30 to 70%, then the procedure just described, if it were legal, would have to reduce the cost by at least 90%.
2. IMPROVING THE COLOR OF A DIAMOND
The color of a diamond can be artificially changed in two ways:
- irradiation in a nuclear reactor or electron accelerator,
- combined exposure to high temperature and high pressure (HTHP).
The first method only makes it possible to enhance, not change the color, usually by converting a J diamond to a Z diamond, resulting in a stone with a more intense fancy color. So you can get bright yellow, orange, red, pink, blue, purple and green stones.
Since the first dyeing method only produces a thin color shell, it is applicable to diamonds that have already been cut and polished.
HTHP, on the other hand, is used to brighten or remove the color of both the rough diamond and the finished diamond. But not all diamonds are suitable for such processing.
The improved color usually remains unchanged during subsequent daily wear of the jewelry.
Prolonged exposure to a very high energy electron beam results in a color transformation to a very dark brown. These diamonds are called black diamonds on the market. For dyeing black, diamonds with very significant inclusions are usually used, giving which any color that retains transparency practically loses its meaning. The cost of black diamonds usually ranges from $ 100-120 per carat and up to several thousand dollars per carat, depending on the quality of the raw materials and the quality of cutting and finishing. For a black diamond, the quality of polishing and the presence or absence of large cavities inside, which can be seen as light spots, are of fundamental importance.
HIGH TEMPERATURE, HIGH PRESSURE - HTHP
Thanks to HTHP technology, invented by General Electric in 1999, the color of some brown diamonds can be significantly improved - the brownish color can be weakened or removed, and the discoloration is stable over time, the treatment itself does not leave marks. According to the company's scientists, natural diamonds were exposed to geophysical forces during their movement to the earth's surface, causing deformation of atomic bonds in their crystal structure. They argue that natural diamonds, when processed with HTHP, spontaneously return to their original state, and their crystal structure is restored, and the stone becomes lighter than it was when it was mined.
HTHP processing uses pressures up to 70,000 atmospheres and temperatures up to 2,000 ° C. General Electric applies a thin "GE POL" laser stamp to the inner face of the discolored diamond, where POL is an acronym for partner company Pegasus Overseas Ltd. This inscription can be sanded down, so its absence cannot be a sign that the diamond has not been discolored.
The most suitable for HTHP processing are diamonds of physical type IIa, which do not contain impurities of nitrogen, which are very rare (less than 1% of all diamonds). They produce diamonds with the highest color D-E-F. Diamonds of physical type Ia, Ib are less suitable for processing by the HTHP method, they produce diamonds with a color no higher than G-H, most often J-I. It is possible to distinguish diamonds by physical type by their spectra, and spectrometers (FTIR) and Raman spectroscopes are in gemological laboratories. In this way, specialists from well-equipped gemological laboratories can identify diamonds that may have been exposed to HTHP processing.
The presence of a diamond cut should always be indicated on its certificate and warranty. But never - you know - NEVER the appraised value is indicated on the certificate! The presence of an assessed or insured value in a certificate is 100% proof that either the stone is not the one they are talking about, or the certificate is fake and was leaked by one of the hundreds of pseudo-laboratories that have never been recognized by anyone .. There are a lot of such in the USA. In Asia, too.
Be careful .. The guarantee that you buy what you buy can only be a GIA or EGL certificate. Their certificates are not falsified, they have personal signatures of an expert, personal numbers that can be verified via the Internet. In the past 10 years, most of the GIA certified diamonds over 0.5 carats have also been laser engraved with the certificate number, not on the surface, but inside the diamond. It is impossible to grind or fake it.
Unfortunately, IGI, HRD, AGA, ACA, AIGS, TGS certificates have become objects of numerous forgeries in recent years.
Photo "Fawn-breasted Brilliant (Heliodoxa rubinoides) in Ecuador" can be used for personal and commercial purposes according to the conditions of the purchased Royalty-free license. The image is available for download in high resolution quality up to 4896x3264.
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