The June birthstone is uniquely defined by a trio of gemstones, each offering distinct aesthetic and symbolic value. Among them, alexandrite stands apart as a modern marvel, renowned for its extraordinary color-changing phenomenon. This rare variety of chrysoberyl shifts from a vibrant green in daylight to a rich red under incandescent light, a property that has captivated collectors and gem enthusiasts since its discovery in the 19th century. As a June birthstone, alexandrite embodies themes of transformation, duality, and good fortune, making it a compelling choice for those born in this month. The following article provides a comprehensive exploration of alexandrite, detailing its historical origins, geological formation, gemological properties, cultural significance, and practical care, based exclusively on the provided source materials.
History and Lore
Alexandrite’s history is relatively recent compared to ancient gems like pearls, but its origin story is steeped in imperial Russian lore. The gemstone was discovered in the Ural Mountains of Russia in the early 1830s. According to historical accounts, it was found on the future Tsar Alexander II’s birthday, leading to its namesake. The stone’s dramatic color change—green by day and red by candlelight—was seen as a natural embodiment of the Russian imperial colors, further cementing its status. This serendipitous discovery and its striking visual property quickly made it a favorite of the Russian aristocracy.
As a modern birthstone, alexandrite was added to the list of June birthstones in the 20th century by the American Gem Trade Association. The traditional birthstone for June was pearl, with moonstone added later to provide variety. Alexandrite’s inclusion was a response to consumer demand for gems with greater rarity, distinct color, and higher value. Its addition reflects a shift in the birthstone tradition, which has evolved over centuries to incorporate both historical precedent and contemporary market preferences. Today, alexandrite is celebrated as one of the most valuable and sought-after gems in the world, prized for its scarcity and mystical color shift.
Geological Formation and Sources
Alexandrite is a variety of the mineral chrysoberyl, with the chemical formula BeAl₂O₄. Its formation requires a unique geological environment. Chrysoberyl typically forms in metamorphic rocks, where beryllium and aluminum are present under high temperature and pressure. The specific conditions that produce alexandrite involve the presence of chromium ions during its crystallization. These chromium ions are responsible for the stone’s characteristic color change, as they absorb light in specific wavelengths.
The primary and most historically significant source of alexandrite is the Ural Mountains in Russia. The deposits discovered in the 1830s produced the finest quality gems, which are now exceedingly rare and command premium prices. Russian alexandrite is considered the benchmark for quality, with its vivid color change and clarity. Over time, other deposits have been found, including sources in Brazil, Sri Lanka, and East Africa. While these newer sources yield alexandrite, the gems often differ in color characteristics; for example, some Brazilian alexandrite may show a more bluish-green to violet-red shift, and material from Sri Lanka might have a less pronounced color change. The rarity of high-quality natural alexandrite, especially from the original Russian localities, contributes significantly to its status as one of the most valuable gemstones in the world, often exceeding the per-carat cost of diamonds.
Gemological Properties
Alexandrite possesses a distinct set of physical and optical properties that define its character and value.
Color and Optical Phenomenon: The most defining feature of alexandrite is its pleochroism, specifically a dramatic color change. Under natural daylight or fluorescent light, alexandrite appears greenish-blue to green. Under incandescent light or candlelight, it shifts to a purplish-red or raspberry-red color. This phenomenon is caused by the presence of chromium (Cr³⁺) ions in its crystal structure, which create absorption bands in the visible spectrum. The intensity and quality of the color change are critical factors in determining the gem’s value; the most prized stones exhibit a strong, distinct shift from an attractive green to a rich red.
Hardness and Durability: On the Mohs scale of mineral hardness, alexandrite ranks at 8.5. This makes it an exceptionally durable gemstone, suitable for a wide range of jewelry applications, including rings that are worn daily. Its hardness is second only to corundum (ruby and sapphire) and diamond among gemstones commonly used in fine jewelry. This durability ensures that alexandrite jewelry can withstand normal wear and tear, though as with all fine gems, it is advisable to avoid hard impacts.
Crystal System and Refractive Index: Alexandrite crystallizes in the orthorhombic system. It has a refractive index ranging from approximately 1.746 to 1.755, which contributes to its brilliance when cut properly. Its specific gravity typically falls between 3.71 and 3.75. These properties are used by gemologists to identify natural alexandrite and distinguish it from synthetic or simulant materials.
Clarity and Inclusions: Natural alexandrite often contains inclusions, which are considered part of its character. Common inclusions may include fine silk (rutile needles), which can sometimes contribute to a softening of the color change, or small crystals of other minerals. Eye-clean alexandrite (with no visible inclusions to the naked eye) is rare and commands a significant premium. The presence and type of inclusions are key factors in gemological certification and valuation.
Cut and Carat Weight: Alexandrite is typically cut into faceted shapes like rounds, ovals, or cushions to maximize its brilliance and showcase its color change. Because of its rarity, larger stones are exceptionally valuable. Fine-quality alexandrite over one carat is considered rare, and stones over five carats are museum-quality specimens. The cut must be carefully executed to balance color saturation, brilliance, and the visibility of the color change from different viewing angles.
The following table summarizes key gemological properties of alexandrite as derived from the provided sources:
| Property | Description / Value |
|---|---|
| Mineral Species | Chrysoberyl |
| Chemical Formula | BeAl₂O₄ (with Chromium impurities) |
| Color Change | Green in daylight to red in incandescent light |
| Hardness (Mohs) | 8.5 |
| Crystal System | Orthorhombic |
| Refractive Index | 1.746 – 1.755 |
| Specific Gravity | 3.71 – 3.75 |
| Primary Source | Ural Mountains, Russia (historical) |
| Other Sources | Brazil, Sri Lanka, East Africa |
Symbolism and Metaphysical Beliefs
Alexandrite’s unique color-change property has endowed it with rich symbolism and a variety of metaphysical beliefs, which are often linked to its duality. The shift from green to red is seen as a metaphor for balance and transformation. In Russian lore, the stone’s colors represented the national flag, but on a personal level, it came to symbolize the balance between the material and spiritual worlds, or between different aspects of one’s personality.
Metaphysically, alexandrite is associated with joy, luck, and creativity. It is believed to stimulate intuition and encourage personal growth, making it a stone of transformation. For those born in June, particularly under the sign of Gemini, the gem’s duality resonates with the sign’s characteristic versatility and ability to adapt. Some traditions hold that wearing alexandrite can boost creativity and bring good fortune, aligning with its historical status as a stone of emperors and aristocrats.
While these beliefs are part of the gem’s cultural heritage and are widely cited in popular sources, it is important to note that they are not scientifically verified. In formal gemology, the value of alexandrite is determined by its physical properties and rarity. However, for many enthusiasts and wearers, the symbolic meanings add a layer of personal significance to the gem, enhancing its appeal as a June birthstone.
Care and Cleaning
Due to its excellent hardness and durability, alexandrite is relatively easy to care for compared to many other gemstones. Its Mohs hardness of 8.5 means it is resistant to scratching by most common materials, including dust and quartz. However, like all fine jewelry, it should be protected from sharp blows and extreme temperature changes, which could potentially cause fractures, especially if the stone has significant inclusions.
Cleaning: The safest method to clean alexandrite jewelry is with warm water, a mild dish soap, and a soft brush. Gently scrub the stone and its setting to remove any oils or dirt. Avoid using harsh chemicals, such as bleach or ammonia, as these can damage the metal setting or affect the gem’s surface over time. Ultrasonic cleaners are generally safe for alexandrite, but it is advisable to avoid them if the stone has known fractures or significant inclusions. Steam cleaners should be used with caution, as sudden temperature changes can be risky.
Storage: When not in use, store alexandrite jewelry separately from other gemstones to prevent scratching. A soft cloth pouch or a compartmentalized jewelry box is ideal. Given its value and rarity, it is also prudent to have alexandrite jewelry insured and periodically inspected by a professional jeweler to ensure the setting remains secure.
Conclusion
Alexandrite is a remarkable June birthstone that combines scientific intrigue with historical significance and metaphysical symbolism. Its discovery in the Ural Mountains and its imperial Russian heritage have secured its place in gemological history, while its addition to the modern birthstone list in the 20th century highlights its enduring appeal. As a variety of chrysoberyl, alexandrite is distinguished by its exceptional hardness, brilliant color change, and extreme rarity, making it one of the most valuable gems in the world. For those born in June, it offers a unique and powerful symbol of transformation and balance. While its metaphysical properties are a matter of personal belief, its physical and optical characteristics are firmly grounded in science, ensuring its status as a prized gem for collectors, jewelers, and enthusiasts alike.