Alexandrite (the gem version of Beryllium) is one of the world’s most expensive gemstones. It’s prized because it has color changing-properties. In natural light it can look blue to blue-green, but under indoor light it looks red. Its hardness, 8.5 on the Mohs scale, makes it particularly appropriate for jewelry, and its relative rarity also creates high demand for the stone.
There’s a wonderful legend attached to how Alexandrite was discovered, and also how it came by its present name. As the myth goes, the gem was discovered in 1834 on the sixteenth birthday of the later Russian Czar, Alexander II. The gem was thus named after Alexander by its discoverer, Nils Gustoff Nordenskjold, a Finnish geologist.
This myth proves not to be true, and it appears Nordenskjold was sent some samples from another geologist. Nordenskjold thought he was looking at emeralds, but couldn’t understand how an emerald could have such a different hardness. Emeralds typically have a hardness of 7.5 to 8 on the Mohs scale. He then probably discovered the color changing properties of the stone, but did not name the stone alexandrite. Instead records show he called the stone diaphanite.
Count Lev Alekseevich Perovskii is credited with bringing the stone to the Russian royal family and possibly renaming it. This occurred well after Alexander II’s sixteenth birthday. Perhaps the Tsar had a right to demand the name change since the earliest supply of alexandrite was found in the Ural Mountains. Today, mines in India, Brazil, Zimbabwe, and Myanmar have found good deposits of alexandrite. Myanmar’s mines are particularly noted for the strong color-changing properties of their gems, though the stones mined there hardly ever exceed a carat in size.
Price on alexandrite is exceptionally high. One-half to a full carat alexandrite of top quality can cost as much as $15,000 US Dollars (USD). Quality is determined not only by lack of flaws but also the amount to which the stone changes color. Therefore you’ll probably find the best stones, especially in smaller sizes come from Myanmar. Stones exceeding the one-carat size have sold for as much as $100,000 USD. These gemstones rarely are larger than five carats, especially in unflawed form.
Most people are interested in the color-changing abilities of alexandrite, and especially want to know why it changes colors. The crystalline structure of the gem explains its special ability. The stone has what are called doubly refractive crystals, which create different light refraction under natural or artificial light conditions. This is called pleochroism. Light is refracted (bent) and follows through different pathways depending upon its type or polarization. Thus sunlight creates a different path through the stone than does indoor light and creates what is called a diochroic effect (two colors exhibited at different times).
Frequently Asked Questions
What is alexandrite and why is it unique?
Alexandrite is a rare gemstone known for its remarkable color change property, shifting from green in daylight to red in incandescent light. This chameleon-like behavior is due to its complex chemical composition, which includes elements like chromium, iron, and titanium. Its rarity and distinctive color change make it highly sought after in the gem market.
Where is alexandrite found, and how rare is it?
Alexandrite was first discovered in Russia's Ural Mountains in the 1830s. Today, it can also be found in Brazil, Sri Lanka, and East Africa, but remains extremely rare. High-quality alexandrite is more scarce than diamonds, making it one of the most valuable gemstones on the market, according to gemological resources.
How is the value of alexandrite determined?
The value of alexandrite is primarily determined by its color change quality, clarity, cut, and carat weight. The more distinct and dramatic the color change, the more valuable the stone. Clarity is also crucial, as inclusions can detract from its beauty and desirability. Larger stones are exceedingly rare, thus commanding higher prices.
Can alexandrite be synthesized or treated?
Yes, synthetic alexandrite exists and is created in laboratories to mimic the natural stone's color change. These lab-grown stones offer a more affordable alternative to natural alexandrite. Treatments on natural alexandrite are less common, but some stones may be oiled or filled to improve clarity, which should be disclosed by sellers.
What are the uses of alexandrite in jewelry?
Alexandrite is often set in rings, earrings, pendants, and other fine jewelry. Its unique color-changing property makes it a favorite for bespoke and high-end pieces. Due to its hardness of 8.5 on the Mohs scale, it is suitable for everyday wear, although care should be taken to protect it from hard knocks.
How should I care for my alexandrite jewelry?
To care for alexandrite jewelry, clean it with warm soapy water and a soft brush, avoiding harsh chemicals and ultrasonic cleaners. Store it separately to prevent scratches from harder gemstones. It's also wise to have a professional jeweler check the settings periodically, as everyday wear can loosen the gem over time.
