ALEXANDRITE

OVERVIEW

Alexandrite, with its chameleon-like qualities, is a rare variety of the mineral chrysoberyl. Its color can be a lovely green in daylight or fluorescent light, changing to brownish or purplish red in the incandescent light from a lamp or candle flame. This is a result of the complex way the mineral absorbs light.

Alexandrite’s dramatic color change is sometimes described as “emerald by day, ruby by night.” Other gems also change color in response to a light-source change, but this gem’s transformation is so striking that the phenomenon itself is often called “the alexandrite effect.”

Alexandrite is also a strongly pleochroic gem, which means it can show different colors when viewed from different directions. Typically, its three pleochroic colors are green, orange, and purple-red. However, the striking color change doesn’t arise from the gem’s pleochroism, but rather from the mineral’s unusual light-absorbing properties.

Because of its scarcity, especially in larger sizes, alexandrite is a relatively expensive member of the chrysoberyl family. It shares its status as a June birthstone with cultured pearl and moonstone.

• Mineral: Chrysoberyl
• Chemistry: BeAl2O4
• Color: Bluish green in daylight, purplish red in incandescent light
• Refractive Index: 1.746 to 1.755
• Birefringence: 0.008 to 0.010
• Specific Gravity: 3.73
• Mohs Hardness: 8.5

The spectacular Ural Mountain deposits were eventually mined out, and now most alexandrite comes from Brazil, Sri Lanka and East Africa. The newer deposits contain some fine-quality stones, but many display less-precise color change and muddier hues than the 19th century Russian alexandrites. Because of its scarcity, especially in larger sizes, fine-quality alexandrite is one of the more expensive colored gems.

This June birthstone is relatively hard—8.5 on the Mohs scale. It has excellent toughness and no cleavage, which is a tendency to break when struck. This makes it a good choice for rings and other mountings subject to daily wear. An alexandrite engagement ring would be a unique gift for a bride-to-be born in June. Although it is best to clean your June birthstone in warm, soapy water, ultrasonic and steam cleaners are usually safe as well.

June is a month for celebrations, be it weddings, anniversaries, graduations or birthdays. And what better way to celebrate than with a June birthstone. Those who were born in June are lucky to have three gorgeous birthstones to choose from. Now you know how to pick one of these June birthstones for yourself or a loved one born in the month of June.

Alexandrite is a birthstone for June, along with pearl and moonstone. Alexandrite is also the gem for the 55th wedding anniversary.

Abundant alexandrite deposits were first discovered in 1830 in Russia’s Ural Mountains. Those first alexandrites were of very fine quality and displayed vivid hues and dramatic color change. The gem was named after the young Alexander II, heir apparent to the throne. It caught the country’s attention because its red and green colors mirrored the national military colors of imperial Russia.

The spectacular Ural Mountain deposits didn’t last forever, and now most alexandrite comes from Sri Lanka, East Africa, and Brazil. The newer deposits contain some fine-quality stones, but many display less-precise color change and muddier hues than the nineteenth-century Russian alexandrites. You’ll still find estate jewelry set with some of the famed Ural Mountain alexandrites. They remain the quality standard for this phenomenal gemstone

Source of Content : www.gia.edu