Alexandrite is a gemstone that has been known to people for less than two centuries. It was first found in 1830 in Russia, in the Urals. It is a type of chrysoberyl mineral. The name was given to the stone on the occasion of the coming of age of the future Tsar of Russia Alexander II. Alexandrites were very popular at the end of the 19th century in the highest circles of Russian society. Together with rubies, sapphires, emeralds, diamonds, they are referred to a special “top” category of the rarest and most expensive precious stones in the world.
What are alexandrites valued for? There are very few of them on the world market, much less than rubies, sapphires or emeralds. Consider the factors that affect beauty and value. One of them is rarity. At the present time, it is quite problematic to find a natural specimen of good quality more than 2 carats on sale. The main problem is to find such alexandrite so that its color is attractive.
Natural alexandrites, in addition to their rarity, have become especially famous for their unique color-changing effect – they change color depending on the type of lighting. This effect is known as “alexandrite”. In daylight (white) lighting, alexandrites have greenish tints, and in the light of an incandescent lamp (yellow), they change to shades of red or pink, purple. The degree of color change in alexandrite is called reverse and can be measured as a percentage (for example, 25%, 50%, 100%). Stones with 100% reverse are the most valuable and extremely rare. Strong pleochroism is also characteristic, when different tones can be observed in the stone from different angles. For example, red, yellowish orange, and green.
The color of alexandrite is the main factor influencing the perception of its beauty. In daylight, the most valuable colors are green and bluish green. The yellowish green color of alexandrite is considered less valuable. Under the light of an incandescent lamp, the most expensive color will be red without additional shades. In addition, alexandrites can be red with a purple or orange tint. Purple alexandrites can be found in Brazil and Tanzania. It should be borne in mind that almost all alexandrites with a good change, even very expensive ones, are dark. And saturated colors can only be seen in bright lighting conditions (for example, under the directional light of a flashlight with a “white” or “yellow” light). If we do not specifically shine on the stone, then often we can observe an inexpressive color, for example, brown with slight shades of pink or green. A stone that changes color from bright green to bright red (not purple) is more of a myth than reality.
Finding a beautifully colored faceted alexandrite is a very difficult task. Only a very small percentage of specimens in “everyday” lighting will have good color. The color of alexandrite in photographs is often embellished, so you should not completely trust the colorful photos in books and on the Internet. When photographing, the color is often distorted, the shades are not those that we see in reality. Therefore, the photos of alexandrite in most cases “hold out” later in the photo editor stronger in green or red colors. At the same time, the stones in the photographs often turn out to be quite beautiful. In real life, these alexandrites can differ significantly from what color you saw in the photo.
“ Practical advice. When buying alexandrite, look at the color in different lighting conditions first. The most important thing in this case is that you like the observed colors. Swing the stone in tweezers or in your hands, looking at it from the side of the platform. Check out the colors and reverses under different lights, by the window or outside during the day, and under an incandescent lamp. You can use a variety of white and yellow flashlights. Note for yourself how light or dark the specimen you have chosen is, as well as its saturation, distribution of color throughout the volume of the stone and additional color shades. You can see the color of a stone under mixed lighting using two types of light sources at the same time. The beauty of a stone depends very much on its color. “
The next factor to be judged is the purity of the alexandrite. This gemstone belongs to the type for which the content of not a very large number of inclusions and cracks is characteristic. It is characterized by gas-liquid veils. Absolutely pure specimens, without internal heterogeneities, are quite rare in nature. Opaque alexandrites are used for making cabochons.
“Practical advice. After you have appreciated the color of alexandrite, evaluate its purity. Make sure the specimen is wiped clean and free of surface contamination on the edges. First check the cleanliness with the naked eye. Are cracks or inclusions conspicuous? It is desirable that they are not in the center of the faceted stone. See if defects have a big impact on overall attractiveness? Then, you can look at the transparency of alexandrite in a 10x triplet magnifying glass for a more thorough analysis. At the same time, pay attention to whether there are significant cracks in the sample that extend to its surface. Their presence can affect durability. “
The mass of the stone is the next factor. The larger the natural alexandrite, the higher its cost per carat. Because here the factor of rarity is already influencing: stones of considerable size are found less often than small ones. Basically, alexandrite weighing less than 2 ct is presented on the world market. Alexandrites over 5 carats usually come from Sri Lanka.
“Practical advice. You can roughly estimate how the faceted alexandrite will look when attached to the product. To do this, you need to put a stone on top of your fingers. Wiggle your palm in different lighting conditions and appreciate all the attractiveness of alexandrite as a whole. Do you like it or not? Likewise, by placing several samples on your fingers at the same time, you can compare them to choose the best one. “
Place of Birth
Natural alexandrite is mined mainly at deposits in the following countries: Tanzania, Brazil, India, Sri Lanka. Extraction is periodically carried out in Russia, in the Urals, but the Ural specimens are now very difficult to find on the world market. The Malyshevskoe deposit in the Urals, in addition to alexandrite, is better known for its emeralds. Gem quality alexandrites from Brazil and Tanzania are often bluish green in daylight and reddish purple in incandescent light. Indian and Ceylon specimens are usually yellowish-green in daylight and orange-red in incandescent light. Ural alexandrites can have a good color change from green to crimson red, they are highly valued in the world. This is a kind of brand created by history, because This type of chrysoberyl was first discovered in the Urals and is distinguished by a fairly good gem quality. The record price per carat belongs to the Ural specimen.
The shape and quality of the cut is also an important factor. For natural alexandrites, oval cut is especially popular. But there are, of course, faceted alexandrites and other forms. The proportions of the slope of the angles of the faces should be such that the stone is bright, does not have a large “window” in the center, ie. the light area through which the color “flows”. It happens that Asian cutters try to “pull out” more mass in the finished stone when cutting, while they make “stretched” pavilions (the lower part of the stone). Cabochons are made from opaque or low purity alexandrites. For both cut stones and cabochons, symmetry, correct proportions and good polishing are important.
“Practical advice. Evaluate the attractiveness of the shape and the quality of the cut in general. Pay attention to the symmetry of the stone, whether there is a “window” in the stone, how much it affects beauty. Is the pavilion too “pulled”? Look at the quality of polishing, the absence of marks, scratches and chips on the surface of the stone. Many minor surface defects can be easily repaired with an inexpensive recutting process. “
In the photo: a fragment of the expert opinion from the GRS laboratory
If you have doubts that you have natural alexandrite in front of you, then it makes sense to ask the seller, or order yourself, an expert opinion on the stone from a well-known gemological laboratory. Thorough studies of inclusions and the chemical composition of the stone also sometimes make it possible to determine the country of origin, which can be reflected in the document. Usually, alexandrites are not subjected to any kind of refinement. Only in isolated cases can they be oiled in order to hide cracks. The fact of ennobling of alexandrite is also reported in the expert opinion. Currently, a synthetic analogue is being produced by various methods. Some synthetic alexandrites, not only in color, but also in inclusions, can be very similar to natural ones. Also, garnets may look like jewelry alexandrites, and sometimes sapphires with a color change effect. And those “alexandrites” that were massively sold in Soviet jewelry were actually cheap synthetic corundums or synthetic spinels with a color change effect. You need to be sure that the stone you buy is natural. For expensive specimens, an expert opinion from a reputable laboratory is highly desirable. The most reputable gemological laboratories in the world are GIA, SSEF, Gubelin GemLab, AGL and GRS. In Russia – the Gemological Center of Moscow State University. For expensive specimens, an expert opinion from a reputable laboratory is highly desirable. The most reputable gemological laboratories in the world are GIA, SSEF, Gubelin GemLab, AGL and GRS. In Russia – the Gemological Center of Moscow State University. For expensive specimens, an expert opinion from a reputable laboratory is highly desirable. The most reputable gemological laboratories in the world are GIA, SSEF, Gubelin GemLab, AGL and GRS. In Russia – the Gemological Center of Moscow State University.
Note that in expert opinions, the color of alexandrite in photographs in most cases has little in common with the color of a real stone. In photographs, the color usually looks more attractive due to the processing in the photo editor. You should also not completely rely on the description of the color indicated in the expert opinion. In real life, a stone may have a not so pure “green” and “red” color, but will have additional shades. Due to the peculiarities of the color change effect itself, neither photo nor video can fully convey all the color nuances. Before buying alexandrite, you must definitely see it with your own eyes under different lighting in order to avoid disappointment in its color.
Below is an example of what is the difference in the color of natural alexandrite between photographs in an expert opinion and in reality. In the photo on the left: a fragment of an expert opinion from the reputable AGL laboratory, showing the color of alexandrite under different lighting conditions. The video on the right: the same copy, shot by us under a gemological lamp (“white light”) and using a flashlight with a “yellow light”. As you can see, the green component in this stone is very different from the color in the photograph. If you do not have the opportunity to see the stone yourself before buying, make sure that you work with professionals who will explain to you all the color nuances for such a difficult stone.
“ Practical advice. Check with the seller about the availability of an expert opinion on the stone or a certificate. Note that individuals can buy unmounted alexandrites in Russia without jewelry only if the stone has a Russian certificate. “
Sometimes jewelry alexandrite can contain thin parallel inclusions or channels. If such a stone is processed in the form of a cabochon, then it can be attributed to a separate gemological variety – alexandrite cat’s eye. If a point source of light is directed at such a stone, then on the surface of the cabochon you can see a light strip of light, which will move along the surface of the stone when swaying. Some of the finest cat-eye specimens come from Brazil.
COST OF ALEXANDRITE
The cost of alexandrite depends on the totality of all the factors discussed in the first and second parts of this article. But the most important ones affecting the price are the following: its color, purity and weight. The brighter and more saturated both colors, the more expensive it will be. With an increase in the value of weight, its rarity increases (since small stones are found much more often), and therefore, the cost also increases. Alexandrite without an expert opinion from a reputable laboratory can be cheaper than with an expert opinion, but then there is some risk of natural origin.
It is accepted in the world that the cost of precious stones is often given in US dollars per 1 carat. There are several organizations that produce tabular pricing guidelines based on weight and quality. Before you start analyzing specific market offers on your own, you can find out the approximate level of prices for alexandrite of certain positions in these publications. They can be approximately found, for example, from the Gem Guide magazine, the data in it are given for alexandrite from Brazil. According to data from this magazine for May / June 2015, the cost of alexandrite per carat in US dollars will be in the following ranges (for example, cut samples weighing 3-5 ct), depending on the quality level:
- Low (commercial) quality – 600-2500.
- Good – 3500-6500.
- Very good – 9300-12500.
- Excellent – 17000-22000.
As the weight increases, the price per carat usually increases. In May 2014, alexandrite from Russia, from the Urals, 21.41 ct was sold at Christie’s for 1.5 million USD, which is approximately 70 thousand dollars / ct. This is a record price for 1 ct ever sold at auctions.
How much alexandrite costs for certain quality characteristics can also be understood based on various market offers. In this case, it is necessary to compare the price for very similar specimens of close characteristics. Please note that color distortion is common in photographs. Therefore, the decision to buy an expensive sample is best made by seeing it live, based on the practical recommendations discussed above. Our company can help you with how to choose alexandrite, as well as suggest how much it will cost – contact us![learn_press_profile]