Alexandrite, a gemstone of extraordinary rarity and captivating beauty, holds a unique position in the world of gemology. Known for its dramatic shift from emerald green in daylight to ruby red in incandescent light, it is often poetically described as "emerald by day, ruby by night." This remarkable color-change phenomenon makes it one of the most fascinating and valuable gemstones on the market. As one of the official birthstones for the month of June, alongside pearl and moonstone, alexandrite carries a legacy steeped in imperial history, scientific intrigue, and profound symbolism. Its journey from a chance discovery in Russia’s Ural Mountains to its status as a coveted gem for collectors and jewelry enthusiasts worldwide is a testament to its enduring allure. This article will explore the rich history and lore of alexandrite, its geological origins and primary sources, its defining gemological properties, the symbolism attributed to it, and practical advice for its care and maintenance.
History and Lore
The story of alexandrite begins in the early 1830s, specifically around 1834, with a fortuitous discovery in the Ural Mountains of Russia. Miners searching for emeralds unearthed a green gemstone that, upon closer inspection under different lighting conditions, revealed a startling transformation to a reddish hue. This was not emerald, but an entirely new variety of chrysoberyl. Given the imperial control over all mining activities in Russia at the time, the stone was presented to the royal court. It was subsequently named in honor of the future Czar Alexander II, whose name, derived from the ancient Greek "Aléxandros," means "defender of people" or "protector of men," with "men" referring to mankind rather than gender.
The timing of this discovery was significant. Alexander II, who would later become known for emancipating Russia's serfs, was the heir apparent at the time. The gem's unique color-change property, shifting from green to red, was said to mirror the national colors of the Russian Empire. This symbolic connection, combined with its exceptional beauty and rarity, immediately elevated alexandrite to a gem of great prestige within the Russian aristocracy. Fine Russian alexandrites, characterized by their vivid saturation and dramatic color shift, became the benchmark for quality. Although the original Russian mines are now depleted, the stones from this period are primarily found in private collections and family heirlooms, serving as a historical legacy of the gem's origins.
Beyond its imperial Russian history, alexandrite's journey to becoming a modern birthstone is part of a broader tradition. The modern birthstone list, which includes alexandrite for June, evolved from historical and traditional lists. While traditional birthstones have long been associated with specific months, the modern list has been updated over time to reflect availability and contemporary preferences. For June, the traditional birthstone is pearl, but alexandrite was added as a modern alternative, offering a durable and vibrant option for those born in the month. This inclusion acknowledges alexandrite's unique status and desirability, positioning it alongside other significant gems in the birthstone chart.
Geological Formation and Sources
Alexandrite is a variety of the mineral chrysoberyl, with the chemical composition BeAl₂O₄. Its formation requires a specific geological environment where beryllium and aluminum are present together under the right temperature and pressure conditions. The presence of chromium, which substitutes for aluminum in the crystal lattice, is responsible for the gem's characteristic color-change phenomenon. The chromium ions absorb light in specific ways, causing the gem to appear green in daylight (which contains more blue wavelengths) and red in incandescent light (which is richer in red wavelengths). This precise chemical composition and formation process make natural alexandrite exceptionally rare.
The original and most famous source of alexandrite was the Ural Mountains in Russia, where it was discovered in the 1830s. These deposits produced the finest alexandrites, known for their intense color saturation and clear, vivid shift from green to red. However, these mines were exhausted relatively quickly, and today, Russian alexandrites are rare and command premium prices on the market, primarily available through private collections or antique jewelry.
Due to the depletion of the Russian sources, the global supply of alexandrite now comes from other locations. Significant deposits have been found in Sri Lanka, Brazil, East Africa (including Tanzania and Zimbabwe), India, and Madagascar. While these sources provide alexandrite to meet worldwide demand, the stones from these regions are often described as paler in color when compared side-by-side with the historic Russian material. The color shift may still be present, but the intensity and vividness of the hues are typically less pronounced. Brazilian alexandrite, for instance, is known for its quality, but it rarely matches the legendary saturation of the Russian gems. The rarity of fine, natural alexandrite from any source contributes to its high market value, often exceeding that of rubies and diamonds due to its scarcity and unique properties.
Gemological Properties
Alexandrite is renowned not only for its color change but also for its excellent durability and distinct gemological characteristics. As a variety of chrysoberyl, it possesses a high Mohs hardness of 8.5, making it one of the hardest and most durable gemstones suitable for all types of jewelry, including rings that withstand daily wear. This durability is a key factor in its popularity for fine jewelry.
The gem's optical properties are central to its identity. Alexandrite has a refractive index ranging from 1.746 to 1.755 and a birefringence of 0.008 to 0.010. Its specific gravity is 3.73, which is relatively high for a gemstone. The color-change effect is a direct result of its unique light absorption, with a specific absorption band at 580nm allowing it to shift between red and green under different light sources. In daylight or fluorescent light, fine alexandrite exhibits a bluish green to green hue. Under incandescent light or candlelight, it transforms to a purplish red to red color. This dual-color appearance is the gem's most celebrated and defining feature.
Clarity is another important quality factor. While alexandrite can contain inclusions, as most natural gemstones do, fine quality stones are expected to be relatively clean. The presence of certain inclusions, such as those that create a cat's-eye effect, is also possible. Alexandrite can exhibit both color change and a cat's-eye phenomenon (chatoyancy) in a single gem, a rare combination that adds to its value and appeal.
In terms of treatments, it is important to note that some alexandrites may undergo processes to alter their color, clarity, or durability. However, untreated, natural alexandrite is the most prized. The gem can also have synthetic counterparts, which are created in laboratories and possess the same chemical, physical, and optical properties as natural alexandrite. While lab-created alexandrite is a more affordable option and can be beautiful, it is distinct from natural stone. Simulants, which are materials designed to imitate alexandrite, also exist in the market. For these reasons, certification from a reputable gemological laboratory, such as the Gemological Institute of America (GIA) or the American Gem Society (AGS), is highly recommended when purchasing alexandrite to ensure its authenticity and quality.
The following table summarizes the key gemological properties of alexandrite as detailed in the sources:
| Property | Value / Description |
|---|---|
| Mineral | Chrysoberyl |
| Chemical Formula | BeAl₂O₄ |
| Color (Daylight) | Bluish green to green |
| Color (Incandescent Light) | Purplish red to red |
| Mohs Hardness | 8.5 |
| Refractive Index | 1.746 to 1.755 |
| Birefringence | 0.008 to 0.010 |
| Specific Gravity | 3.73 |
| Key Phenomenon | Color Change (and sometimes Cat's-Eye) |
Symbolism and Metaphysical Beliefs
The symbolism of alexandrite is deeply intertwined with its history and physical properties. Its name, derived from Czar Alexander II, carries the meaning of "defender of the people" or "protector of men," imbuing the gem with a sense of strength and guardianship. The dramatic color change from green to red has been associated with the duality of life, representing the balance between the material and spiritual worlds, or the transition between day and night. This characteristic has led to its association with intuition, creativity, and the ability to adapt to changing circumstances.
In some metaphysical beliefs, alexandrite is considered a stone of good omens and joy. Its ability to change color is seen as a symbol of transformation and the promise of a bright future. For those born in June, wearing alexandrite as a birthstone is believed to bring luck, confidence, and emotional balance. It is also associated with the 55th wedding anniversary, symbolizing a long and harmonious partnership that has endured and transformed over time, much like the gem itself.
While these symbolic meanings and metaphysical beliefs are popular in various cultural and spiritual contexts, it is important to note that they are not established by scientific gemology. The allure of alexandrite, however, is amplified by this rich tapestry of lore, making it a gemstone that is as meaningful as it is beautiful.
Care and Cleaning
Given its high Mohs hardness of 8.5, alexandrite is a very durable gemstone, well-suited for jewelry that is worn regularly. Its toughness is excellent, and it does not have any significant cleavage, meaning it is not prone to splitting along internal planes. This durability makes it relatively easy to care for compared to more fragile gemstones.
To clean alexandrite jewelry, use warm water, a mild soap (such as dish detergent), and a soft brush. Gently scrub the gemstone and its setting to remove any dirt or oils. Rinse thoroughly with clean water to ensure no soap residue remains. It is advisable to avoid harsh chemicals, ultrasonic cleaners, and steam cleaners, as these could potentially damage the stone or its setting, especially if the jewelry contains other materials or has been treated.
When storing alexandrite, it is best to keep it separately from other jewelry to prevent scratches, although its hardness makes it resistant to scratching by most other gems. For valuable or antique alexandrite pieces, professional inspection and cleaning by a jeweler periodically is recommended to ensure the settings remain secure and the gemstone is in good condition.
Conclusion
Alexandrite stands as a testament to nature's artistry, combining remarkable durability with a mesmerizing color-change phenomenon that has captivated humans since its discovery in the 1830s. From its origins in the Russian Ural Mountains, where it was named for a future Czar and became a symbol of imperial splendor, to its current status as a prized June birthstone and a gem for the 55th anniversary, alexandrite's history is as colorful as the stone itself. Its geological rarity, defined by the precise conditions required for its formation, ensures that fine natural alexandrite remains one of the most valuable gemstones in the world. While modern sources in Sri Lanka, Brazil, and East Africa provide alexandrite to the market, the legendary Russian stones continue to set the standard for quality and saturation. For those who wear it, alexandrite is more than a beautiful jewel; it is a symbol of balance, transformation, and enduring strength. Its care is straightforward, and its presence in jewelry, whether in a custom piece or a family heirloom, guarantees a conversation starter that bridges science, history, and legend. As a cornerstone of the June birthstone collection, alexandrite continues to enchant gemstone enthusiasts, jewelry buyers, and students of gemology with its unique blend of beauty, rarity, and lore.