Since our eyes are most sensitive to green light, the balance is tipped to the green side. The strength of the color change is related to the difference in the areas of transmission, relative to the absorption in the yellow. The greater the difference, the stronger the color change. When evaluating alexandrite, pay the most attention to the color change: the more dramatic and complete the shift from red to green, without the bleeding through of brown from one color to the next, the more rare and valuable the stone.
For alexandrite, the quality of the color change is paramount. While the holy grail is a gem whose color changes like a traffic light from green to red, such a stone has yet to be found. In fine examples, the change is typically one from a slightly bluish green to a purplish red. The other important value factors are the attractiveness of the two colors - the more intense the better - the clarity, and the cutting quality.
Because of the rarity of this gemstone, large sizes command very high premiums. Offer Ends Nov Skip to main content. AJS Gems. Alexandrite Gemstone Information. Click here to see all our Alexandrite for sale. There are many reasons, but mainly it comes down to value and choice Color Color Change Refractive Index 1. In the market, alexandrites are found in a variety of shapes and cutting styles. Ovals and cushions are the most common, but rounds and emerald cuts are seen as well, as are fancy shapes.
Alexandrite is generally not treated, although the occasional stone may be treated by oiling or dying. Like many other gemstones, alexandrite emerged millions of years ago in a metamorphic environment.
But unlike many others, its formation required specific geological conditions. The chemical elements beryllium a major constituent in chrysoberyl and chromium the coloring agent in alexandrite have contrasting chemical characteristics and do not as a rule occur together, usually being found in contrasting rock types.
Not only has Nature brought these contrasting rock types into contact with each other, but a lack of the chemical element silica the second most common element in the Earth's crust is also required to prevent the growth of emerald. This geological scenario has occurred only rarely in the Earth's history and, as a result, alexandrite crystals are very scarce indeed. Today, fine alexandrite is most often found in period jewelry since newly-mined gems are extremely rare.
It is well loved by the Russian master jewelers. Master gemologist George Kunz of Tiffany was a fan of alexandrite and the company produced many rings featuring fine alexandrite in the late nineteenth and early twentieth century, including some set in platinum from the twenties. Some Victorian jewelry from England features sets of small alexandrites. Alexandrite is also sometimes available as an unset stone but it is extremely rare in fine qualities. The original source in Russia's Ural Mountains has long since closed after producing for only a few decades and only a few stones can be found on the market today.
Material with a certificate of Russian origin is still particularly valued by the trade. Some alexandrite is found in Sri Lanka and Zimbabwe and Brazil, but supply is unpredictable. For many years, alexandrite was almost impossible to find because there was so little available.
Then in , a new find of alexandrite was made in Brazil at a locality called Hematita. The Hematita alexandrite shows a striking and attractive color change from raspberry red to bluish green. The Brazilian alexandrites showed both a distinctive color change and good clarity and color. Thus the somewhat dulled image of the miraculous stone received another boost. The color of the Brazilian stones is admittedly not as strong a green as that of Russian alexandrite, but the color change is clearly discernible.
Today Hematita is one of the most important deposits of alexandrite in economic terms. Occasionally alexandrite with chatoyancy is discovered there, an effect which has not yet been observed in Russian alexandrite. Alexandrites are also obtained from sources in Sri Lanka. They appear green in daylight and a brownish red in artificial light. The Tunduru area in southern Tanzania has also produced some outstanding specimens since the mids.
Alexandrites are also found in India, Burma, Madagascar and Zimbabwe. Although this stone is still considered a rarity, specialised gemstone dealers do stock it, especially since improved trade relationships between Russia and the rest of the world have ensured a better supply of Russian alexandrites to the market.
Alexandrite remains extremely rare and expensive, but the production of a limited amount of new material means a new generation of jewelers and collectors have been exposed to this beautiful gemstone, creating an upsurge in popularity and demand.
Although Russian alexandrites have the most historical value, fine stones are available from several other deposits. Top stones are extremely rare but all of these deposits occasionally produce exceptional stones. Brazilian stones typically show the best reds under incandescent light but Indian stones are well known for their superior bluish green daylight colors. Tanzania and Madagascar seem to produce the largest stones and some of the stones are exceptional.
There is currently hardly any production of Russian stones. Alexandrite is a very rare gemstone and a fairly modern one as well. Thus it does not share the ancient history and lore of most other gems. One miner gathered some stones, which looked like emeralds and took them back to the camp at the end of the day.
Russian jewelers were fascinated by this rare color-changing gemstone. He produced a series of alexandrite rings between the late 19th and early 20th centuries. Alexandrite was occasionally used for jewelry in Victorian England as well. Brazil, Sri Lanka, and East Africa are now the main sources for alexandrite, though these gems are not as vividly colored as the original Russian gemstones.
Natural alexandrite gemstones are now rarer than diamonds. With its changing color, it is a reminder that life is not only what it seems to be. There are many ways alexandrites are said to aid in physical ailments. They are recommended for those recovering from surgery or a prolonged illness.
They have the ability to aid the system in restoring internal and physical energy. They may also be of value to those who face chronic disorders. Contemporary practitioners of crystal healing claim the gemstone is helpful in treating afflictions of the spleen and pancreas as well as the regeneration of neurological tissues and in treating Leukemia. Alexandrites can aid in centering oneself. Physical Properties and Science of Alexandrite Alexandrite is a variety of the mineral chrysoberyl.
This combination of elements results in the green color of the gemstone. Alexandrite can be almost emerald colored, but is more often yellowish green or brownish green.
This metamorphosis is called Pleochroism. Under such light, such as candlelight, or artificial light, the stone turns red or reddish. This pronounced color change is highly prized. The most valuable alexandrites are brilliant green, and change color to a fiery red under light.
The most drastic color changes are the most desirable, as if you were watching a traffic light change color. Usually there is a color bleed through from one color to the other, or there is too much impurity to start with to permit such a drastic color change. Alexandrite is usually found in sizes smaller than five carats. Sizes over five carats are usually considered large and will command a proportionally higher price. In Ceylon, some of the largest Alexandrites in the world are found, some weighing up to 60 carats each.
These stones are of a darker color. It is exceeded in hardness only by the diamond and corundum. It is because of this, and because it is one of the world's most rare gems, that the Alexandrite can be one of the costliest gemstones in the world. Alexandrites have been found in Russia and in Brazil , though the Brazilian stones do not display as rich a green color as the Russian stones have been known for. They are also found in Sri Lanka, however there as well, the color shades of the stones are not as bright as the Russians.
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