Alexandrite is one of the jewels that can be used as a birthstone for June, the others being pearl and moonstone. Alexandrite is a form of chrysoberyl, which forms in the earth’s crust due to the action of magma. It’s unique in that, unlike other chrysoberyls, Alexandrite contains not only impurities of iron and titanium, but chromium, which is crucial to its value. Pure chrysoberyl is clear and colorless or very pale yellow.
Alexandrite has a hardness on the Mohs scale of 8.5, which means it’s the hardest gemstone behind diamond and corundums like ruby and sapphire.
Alexandrite was first found in April, 1834 in an emerald mine in the Ural mountains. It was named after Tsar Alexander I, who was ruler of Russia at the time. Some historians believe that Alexandrite was discovered by Nils Nordenskjold, a mineralogist from Finaldn and named after Tsar Alexander II, who wouldn’t even become Tsar till 1855. Because the national colors of tsarist Russia were red and green and Alexandrite is both red and green, it was adopted as the country’s national stone.
Alexandrite, besides having a recent history — rubies are mentioned in the Bible — is also quite rare. Its two components, beryllium and chromium, don’t usually occur together in nature.
One amazing thing about Alexandrite is that it changes color. The gem is green or green blue in natural daylight and then turns a dazzling red-violet or purplish red when placed under artificial light. It can do this because of chromium. Chromium absorbs yellow light with great efficiency. Only chrysoberyls that can change their color this way can be called Alexandrite. Unlike some other gems that seem to change color, the change in Alexandrite’s color isn’t dependent on the angle at which the stone is viewed.
The Ural mountains were the major sources of Alexandrite for a long time, till the supply became exhausted. Alexandrite could be found in other places, but none of them possessed that spectacular ability to change color. But around 1987 some very high quality Alexandrite was found in Brazil, even though the colors weren’t as vibrant as the Russian stones. Now and again a stone will be found that displays chatoyancy, a quality where the light in the gem resembles the slit in a cat’s eye. This is an exceedingly rare characteristic.
Other quality Alexandrites can be found in Sri Lanka, Tanzania, India, Zimbabwe, and Madagascar.

Synthetic Alexandrite

The best Alexandrites show the brilliant blue green in natural light and the purple red color in artificial light, with no other colors seen, especially not brown or gray. A stone that can be proven to be from Russia is especially valuable. Even more valuable are Alexandrite stones that weigh more than a carat and are very finely cut. Specimens of Alexandrite that weigh more than three carats are very rare.
June birthstone — Alexandrite is considered by astrologers to be a stone of good luck and is supposed to sharpen the intuition and creativity of its wearer. Synthetic Alexandrite is also made, but these are really examples of corundum with spinel. Alexandrite lasers, which have a wave length of 755 nanometers, are used in cosmetic surgery, often in the removal of unwanted hair.