June’s birthstone lineup is unique in the world of gemology, offering not one, but three distinct options—pearl, moonstone, and alexandrite. Of these, alexandrite stands apart as the rarest and most enigmatic. Discovered relatively recently, its most captivating feature is its ability to change color under different lighting conditions—shifting from a deep green in daylight to a rich red or purplish hue under incandescent light. This remarkable transformation has earned it the poetic moniker “emerald by day, ruby by night.” The gem’s discovery in the 19th century, its association with Russian royalty, and its chemical composition all contribute to its enduring mystique.
In this article, we explore the historical journey, geological properties, cultural significance, and care requirements of alexandrite. Drawing from well-researched and authoritative sources, we present an in-depth look at what makes this gemstone a symbol of rarity, beauty, and historical prestige.
History and Lore
Alexandrite’s history is as fascinating as the gemstone itself. It was first discovered in 1834 in the Ural Mountains of Russia, a region already famed for its emerald deposits. The gem was named in honor of Alexander II, who was about to celebrate his 16th birthday on the day of its discovery. According to some accounts, the first alexandrite was mistaken for emerald by miners, who noticed its green color in daylight. However, when examined under the glow of a campfire, the stone revealed its true nature—shifting to a deep red. This unexpected transformation was attributed to the presence of chromium in the crystal structure, a discovery that would later cement alexandrite’s place in the annals of gemology.
The initial discovery is credited to Finnish mineralogist Nils Gustaf Nordenskiöld, though other contributors to its naming and identification include Russian mineralogist Count L.A. Perovskii and German mineralogist Gustav Rose. Regardless of the exact individual responsible, it was Perovskii who presented the gem to Alexander II on April 29, 1834. This act not only marked the beginning of alexandrite’s association with Russian royalty but also elevated its status as a symbol of national pride, especially given its reflection of the Russian military colors—green and red.
The gem’s color-changing property also inspired various interpretations. In Russian culture, alexandrite was viewed as a symbol of prestige and good fortune. Alexander II himself was said to have worn an alexandrite ring as a talisman. Elsewhere, some cultures believed that the gem's color shift was a warning of impending danger, adding to its aura of mysticism.
By the late 19th century, Russia’s alexandrite deposits had nearly been exhausted. New sources were later discovered in Brazil in 1987, followed by Sri Lanka and Zimbabwe. However, these later deposits generally produce stones with less intense color changes and paler hues compared to the original Russian alexandrites. Today, alexandrite is considered one of the most valuable and sought-after gemstones in the world.
Geological Formation and Sources
Alexandrite is a rare variety of the mineral chrysoberyl, a beryllium-aluminum oxide with the chemical formula BeAl₂O₄. What sets alexandrite apart is its trace amounts of chromium, which is responsible for the green color it exhibits in daylight. The same element is also responsible for the red color in rubies and the green in emeralds. However, the presence of chromium in alexandrite is unique because it enables the gem to exhibit a dramatic color change depending on the light source.
The color change phenomenon is due to the way alexandrite absorbs and re-emits light. In daylight or fluorescent lighting, the chromium in the gem absorbs certain wavelengths of light and reflects the green. Under incandescent light, the emission spectrum changes, and the gem reflects the red. This transformation is not just a visual trick—it is a result of the gem's atomic structure and the specific way it interacts with light.
Alexandrite is formed under high-pressure, high-temperature conditions in metamorphic rock environments. It typically occurs in pockets within basaltic rock formations, where it crystallizes from magma rich in beryllium and aluminum. The presence of chromium in these environments is rare, which is one of the reasons why alexandrite is so uncommon.
Historically, the Urals in Russia were the only known source of alexandrite. These deposits were nearly exhausted by the late 19th century. In the modern era, alexandrite is also mined in Brazil, Sri Lanka, and Zimbabwe. While these new sources have helped to supply the market, the stones from these locations tend to have less vibrant color changes and are generally less valuable than their Russian counterparts.
The rarity of alexandrite is further compounded by its scarcity in large sizes. Stones over one carat with a strong color change are considered among the most valuable in the world. This scarcity, combined with the gem’s unique properties, makes alexandrite a highly desirable and collectible gemstone.
Gemological Properties
Alexandrite is prized not only for its color-changing ability but also for its physical and optical properties. On the Mohs scale of hardness, alexandrite ranks at 8.5, making it harder than garnet (6.5–7.5) but softer than sapphire (9). This hardness makes it suitable for jewelry, though it requires careful handling to avoid scratches or chips, especially from harder gemstones like diamonds or sapphires.
In terms of refractive index, alexandrite has a value of approximately 1.74–1.76. This is relatively high, contributing to its brilliance and fire. However, alexandrite does not exhibit strong dispersion, meaning it does not display the same level of “sparkle” as diamonds or other high-dispersion gems. Instead, its beauty lies in its color change and clarity.
Alexandrite is typically transparent to translucent and is cut in a variety of styles, including round brilliant, emerald, and cushion cuts. The most popular cut for showcasing its color change is the emerald cut, which provides large, open facets that allow for maximum light penetration. The clarity of alexandrite can vary, but the most valuable stones are those that are eye-clean or nearly so, with minimal inclusions.
The most prized alexandrites are those that display the most intense color change—shifting from a vivid green in daylight to a deep red or purplish hue under incandescent light. The quality of the color change is a key factor in determining the gem’s value. Stones that show a weaker or less dramatic shift are less valuable, even if they are otherwise of high quality.
Another important factor in alexandrite’s valuation is its carat weight. Large, high-quality alexandrites are extremely rare and can command very high prices in the market. Stones over one carat with strong color change are considered exceptional and are highly sought after by collectors and connoisseurs.
| Property | Value |
|---|---|
| Chemical Formula | BeAl₂O₄ (with trace chromium) |
| Hardness (Mohs) | 8.5 |
| Refractive Index | 1.74–1.76 |
| Color | Green by day, red/purple by night |
| Cleavage | None |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Typical Cut | Emerald, round, cushion |
| Origin | Russia, Brazil, Sri Lanka, Zimbabwe |
| Most Valuable Feature | Color change |
Symbolism and Metaphysical Beliefs
Throughout history, alexandrite has been associated with a range of symbolic meanings and metaphysical properties. In Russian culture, it was seen as a symbol of good fortune and national pride, particularly during the reign of Alexander II. The gem’s association with the young Czar and its reflection of the colors of the Russian military made it a powerful symbol of imperial prestige.
In other cultures, alexandrite has been linked to themes of transformation and adaptability. The gem’s ability to change color under different lighting conditions is often interpreted as a metaphor for personal growth and the ability to navigate different situations with grace. Some believe that alexandrite helps its wearer to be more flexible and open-minded, adapting to change with ease.
From a metaphysical perspective, alexandrite is considered a stone of balance and harmony. It is said to help bridge the gap between the physical and spiritual worlds, enhancing intuition and emotional stability. Some practitioners believe that alexandrite can aid in the regulation of emotions, helping to calm anxiety and promote a sense of inner peace.
In modern times, alexandrite is also associated with love and relationships. Its color change is often interpreted as a symbol of love that reveals itself in different forms, depending on the circumstances. As a result, alexandrite has become a popular gift for those celebrating anniversaries or expressing deep affection.
Alexandrite is also the recognized gemstone for the 55th wedding anniversary, a testament to its enduring symbolism and emotional significance. Its rarity and beauty make it a fitting choice for a milestone that represents a long and enduring union.
Care and Cleaning
Due to its hardness and durability, alexandrite is suitable for everyday wear in jewelry, but it does require proper care to maintain its beauty and longevity. As with all gemstones, alexandrite should be protected from exposure to harsh chemicals, extreme temperatures, and physical impacts.
When cleaning alexandrite jewelry, it is best to use a soft cloth and mild soap with warm water. Ultrasonic cleaners can be used with caution, as they may cause damage to inclusions or lower-quality stones. Steam cleaners, however, should be avoided, as they can cause thermal shock or damage to the gem’s structure.
Alexandrite should also be stored separately from other gemstones, particularly those that are harder, such as diamonds or sapphires. This helps to prevent scratches and ensures that the gem remains in pristine condition.
When handling alexandrite, it is important to be aware of the lighting conditions. The gem’s color change is most dramatic under incandescent light, so it may appear different in various settings. This is not a sign of damage or degradation but rather a natural characteristic of the stone.
For those who own alexandrite jewelry, it is advisable to have it professionally inspected and cleaned by a qualified jeweler on a regular basis. This ensures that any potential issues, such as loose settings or wear on the stone, are addressed promptly.
Conclusion
Alexandrite is a gemstone of extraordinary rarity, beauty, and historical significance. Discovered in the Ural Mountains of Russia in 1834, it was named in honor of Alexander II and quickly became a symbol of Russian imperial pride. Its most captivating feature is its ability to change color—from a deep green in daylight to a rich red or purplish hue under incandescent light—a phenomenon caused by the presence of chromium in its crystal structure.
Despite its relatively recent discovery, alexandrite has become a highly sought-after gemstone, valued for its unique properties and limited availability. While new sources in Brazil, Sri Lanka, and Zimbabwe have helped to meet market demand, Russian alexandrites remain the most prized for their vibrant color change and exceptional quality.
In addition to its geological and optical properties, alexandrite carries deep symbolic meaning. It has been associated with themes of transformation, adaptability, and emotional balance, making it a popular choice for those seeking both aesthetic and spiritual significance. As the June birthstone, it represents a rare and beautiful way to celebrate those born in the month of June.
Whether admired for its scientific properties, historical significance, or metaphysical qualities, alexandrite remains one of the most intriguing and valuable gemstones in the world. Its combination of rarity, beauty, and symbolism ensures that it will continue to captivate gemstone enthusiasts and collectors for generations to come.