Alexandrite Gemstone Information



The history of Alexandrite is an interesting one.This very rare gemstone is named after the Russian tsar Alexander II (1818-1881). The very first crystals were said to have been discovered in April 1834 in the emerald mines near the Tokovaya River in the Urals. Legend is that the discovery was made on the day the future tsar came of age. Since it shows both red and green, the principal colors of old Imperial Russia, it inevitably became the national stone of tsarist Russia. Although alexandrite is a relatively young gemstone, it certainly has a noble upbringing.

Alexandrite is a form of chyrsoberyl that displays a color change under varying lighting. Alexandrite contains chromium while ordinary chrysoberyl is colored by iron, so spectroscopic analysis can be used to identify alexandrite. Fluorescence is another property that differentiates the two gems. Chrysoberyl owns its yellowish color to iron and usually shows no fluorescence. The red fluorescence of alexandrite can be observed using the
crossed filter method.

The prices and value of Alexandrite varies depending on the size and quality of the gemstone. The most important factors in valuing alexandrite are strength of the color change, color saturation under varying lighting conditions, clarity and size. Alexandrites with a strong color change are very valuable and clean stones over 1 carat are very rare.

Cat's Eye Alexandrite
Alexandrite Cat's Eye, Tanzania

 

Why Buy Loose Gemstones Instead of Pre-Set Jewelry?
 
There are many reasons, but mainly it comes down to value and choice...

When buying your gemstones loose instead of a pre-set stone, you can be sure that you are getting the best value for your money. Loose gemstones are less expensive, a better value, and you can really see what you are paying for.  The most important part of getting the right price and finding the best value is to first see what you're getting. A jewelry setting will hide the inclusions inside a gem, and can deepen or brighten its color.  With a loose stone you can much more easily inspect the gem and see it for what it really is.  In this way you can get a better idea of its true worth and be sure you are paying a fair price.

The second advantage of buying a loose gemstone is choice.  You are free to pick the exact color, cut, shape and variety of the stone for the setting of your dreams, be it yellow gold, white gold, platinum or silver; prong set or bezel set with diamond accents. You can experience the joy of creating your very own, one-of-a-kind jewelry design. Choose from a variety of jewelry settings and styles to create a completely original presentation that will perfectly suit your individual gemstone and will be as unique as you are!

 

                                Alexandrite and Diamond Ring in 18k White GoldAlexandrite, Amethyst and Diamond Ring in 18k White Gold         

 


Attributes

  
Origin Madagascar, Russia, Tanzania, Sri Lanka, Rhodesia, Brazil, India, Burma, Zimbabwe, Zambia.
Color Color Change
Refractive Index 1.741 - 1.760
Chemical Composition   BeAl2O4
Hardness 8.5
Density 3.73
Crystal Structure Orthorhombic
Month June
 

Alexandrite is a variety of the mineral chrysoberyl (a cyclosilicate) which is an aluminate of beryllium. Chrysoberyl is usually transparent to translucent and sometimes chatoyant. The most valuable variety of chrysoberyl is alexandrite. Because of alexandrite's unique ability to absorb certain elements of the color spectrum, it can look greenish-bluish-grey in daylight and reddish-purple (raspberry red) under artificial light. Alexandrite's characteristic green to red color change results from small scale replacement of aluminium by chromium oxide. Natural alexandrite is very rare. The finest alexandrite crystals ever found came from the Tokovaya river deposit, and the greatest alexandrite specimen ever found is housed in Moscow's Fersman Mineralogical Museum. Alexandrite has a hardness of 8.5 on the Mohs scale so it is a very durable gem. Alexandrite has a refractive index of 1.745.

The refractive index (RI), measured using a refractometer, is an indication of the amount light rays are bent by a mineral. Birefringence is the difference between the minimum and maximum RI. When birefringence is high, light rays reflect off different parts of the back of a stone causing an apparent doubling of the back facets when viewed through the front facet.

Most gems have a crystalline structure. Crystals have planes of symmetry and are divided into seven symmetry systems. The number of axes, their length, and their angle to each other determine the system to which a crystal belongs.  Alexandrite crystalizes in the orthorhombic crystal system, with a "tabular", striated, and/or prismatic crystal habit, forming pseudo-hexagonal or cyclic ("iron cross" and "cog wheel") twinning.

  

Color

A distinct color change is the primary qualification for a chrysoberyl to be considered alexandrite.  Alexandrite is a trichroic gemstone which may absorb and reflect light differently in each of its three optical directions. However, it is not the trichroism that is responsible for the remarkable change. The color change phenomena is a result of the presence of chromium +3 ions and the way they are absorbed and reflected. In rubies the chromium absorption band is around 550 nanometers and in emeralds, the band is around 600nm. In alexandrite, where the band is at 580nm and right between ruby red and green emerald, the stone is balanced between them. When the light is balanced (daylight), the stone will be green but when the light source is reddish (incandescent), the stone appears red. Daylight, is more equally balanced. 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.



Cut
 
 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.
 

Treatments
 
Alexandrite is generally not treated, although the occasional stone may be treated by oiling or dying. 
 
AJS Gems fully discloses any and all treatments to our gemstones.
 

Sources
   
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 1987, 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 mid-1990s. 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.
 
Which Alexandrites are Best?

Although Russian alexandrites have the most historical value, fine stones are available from several other deposits. Brazil, India, and Tanzania produce the bulk of today’s production but alexandrites are also found in Sri Lanka and Madagascar. 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.
 
 
Mythology
 
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.

The story of the stone’s discovery goes like this: Miners were working alone in the mountains one day, collecting emeralds. One miner gathered some stones, which looked like emeralds and took them back to the camp at the end of the day. But in the light of the campfire, the stones shone a brilliant shade of red! The miners were perplexed. When morning came and they saw that the stones were green again in the light, they realized that they had found a new and mysterious gem.

In 1839, the stones were identified and named "alexandrites." Because the stones appeared green or red, the same colors as Old Imperial Russia’s military colors, the stone became the national stone of tsarist Russia. In time, alexandrite would become one of the most prized gemstones amongst Russian Aristocracy. However, the abundance of alexandrites in Russia did not last forever. Practically all of Russia’s alexandrite was mined during the 19th Century. However, just when the gems were thought to be headed to extinction, even larger deposits were found in Ceylon, now Sri Lanka, the island North of India. Later on, Brazil became another contributor to the world supply of the stone.

While Alexandrites found favor in the jewelry salons of St. Petersburg, Russia and Paris, France, it was America’s Tiffany Company that seems to have done the most to popularize the gem. George Kunz, Tiffany’s master gem buyer, fell absolutely in love with the gem and traveled to Russia in search of it. No one knows exactly how much of the gemstone he bought, but Tiffany had reserves so large, that it cornered the market on the stone for decades.

Since the discovery of alexandrite, the gemstone has been thought to bring luck, good fortune and love.

In Russia, it is considered to be a stone of very good omen. It is believed to bring balance in the interaction between the physical manifest world and the unmanifest spiritual, or astral world. It opens the crown chakra, bringing one access to the warm, healing energy and love of the universe. It is also said to strengthen intuiion, creativity, and imagination.

Alexandrite encourages romance. It is also said that through the stone, joy enters the lives of people with too much self-discipline. The stone reminds us of our purpose in life and our origin. It gives hope to those who are in despair about their lives. It brings strength and constantly reminds them of the light.

With its changing color, it is a reminder that life is not only what it seems to be.

Alexandrite is the birthstone for the month of June and the Anniversary stone for the 55th year of marriage.


AJS Gems Wholesale Loose Alexandrite

Highly competitive prices-The widest choice of varieties-Satisfaction quality guaranteed
Shop with confidence no risk - Money - Back - Guarantee
SSL Secure Payments - Fast FedEx delivery 2-4 working days
 
 
 Email to a Friend Friend's Name:
Friend's Email:
Your Name:
Message: