Alexandrite, a remarkable variety of the mineral chrysoberyl, holds a distinguished position as a primary birthstone for June. Celebrated for its captivating ability to change color under different lighting conditions, this gem boasts a fascinating history, unique geological origins, and a growing presence in the world of fine jewelry. This article will delve into the history, geological formation, gemological properties, and care of this exceptional gemstone, drawing solely from available sources.
History and Lore
The story of alexandrite is intimately linked to the Russian Empire. Discovered in 1830 within the Ural Mountains of Russia, the gem quickly gained prominence due to its striking color change – displaying a vibrant green to bluish-green in daylight or fluorescent light, and transforming into an intense red to purplish-red under incandescent light. This remarkable characteristic did not go unnoticed; the gem was named in honor of the young Alexander II, then heir apparent to the throne, as its colors mirrored the national military colors of imperial Russia.
The initial discovery coincided with a period of national pride, further cementing alexandrite’s status as a significant gemstone within the country. While historical records indicate the gem was quickly embraced, its story extends beyond its initial Russian origins. Ancient traditions connect birthstones to religious significance, with the first records of associating gemstones with meaning found in the Book of Exodus, detailing twelve precious stones representing the twelve tribes of Israel. Though not directly linked to alexandrite’s initial discovery, this historical context illustrates the long-standing human fascination with the symbolic power of gemstones.
The modern assignment of alexandrite as a June birthstone is a more recent development. In 1952, the Jewelry Industry Council of America officially added alexandrite to the list of birthstones for June, alongside pearl and moonstone. This addition reflects a broader trend of assigning multiple gemstones to each month, moving away from the traditional one-to-one correspondence. Today, birthstone lists are categorized as ancient, traditional, and modern, with the modern list being the most recently formulated.
Geological Formation and Sources
Alexandrite’s formation is a relatively rare geological event, contributing to its scarcity and value. It is a variety of chrysoberyl, a beryllium aluminum oxide mineral. The presence of chromium impurities within the chrysoberyl structure is responsible for the gem’s remarkable color-changing ability.
Historically, the Ural Mountains in Russia were the primary source of alexandrite. However, these deposits were eventually mined out. Currently, most alexandrite originates from Brazil, Sri Lanka, and East Africa. While these newer deposits yield some fine-quality stones, they often exhibit less precise color change and muddier hues compared to the 19th-century Russian alexandrites. The scarcity of larger, high-quality alexandrites further elevates its value within the gem market.
The formation of alexandrite is linked to specific geological conditions, often found in metamorphic rocks. The presence of beryllium, aluminum, chromium, and oxygen in the right proportions, combined with specific temperature and pressure conditions, is crucial for its creation.
Gemological Properties
Alexandrite possesses a unique combination of gemological properties that contribute to its desirability. It registers 8.5 on the Mohs scale of hardness, indicating excellent durability and making it suitable for everyday wear, even in rings. It also exhibits excellent toughness and lacks cleavage, meaning it is resistant to breaking when struck.
The most defining characteristic of alexandrite is its color change. This phenomenon, known as the Alexandrite effect, is due to the gem’s ability to absorb different wavelengths of light depending on the light source. The ideal alexandrite displays a vivid green to bluish-green in daylight or fluorescent light and an intense red to purplish-red in incandescent light. The more complete and distinct the color change, the more valuable the stone.
Some alexandrites also exhibit chatoyancy, or the cat’s-eye effect, when oriented with long, thin inclusions parallel to each other. This adds another layer of visual interest to an already captivating gem.
Here's a summary of key gemological properties:
| Property | Value |
|---|---|
| Hardness (Mohs) | 8.5 |
| Toughness | Excellent |
| Cleavage | None |
| Chemical Formula | BeAl₂O₄ |
| Color Change | Green to Red |
| Phenomenon | Alexandrite Effect, Chatoyancy |
Symbolism and Metaphysical Beliefs
While the sources do not detail extensive metaphysical beliefs surrounding alexandrite, the historical context of birthstones suggests a connection to astrological alignment and the influence of planetary energies. The tradition of associating gemstones with zodiac signs dates back to ancient scholars like Flavius Josephus and St. Jerome, who believed the twelve gems in the Breastplate of Aaron corresponded to the twelve months and zodiac signs.
The practice of wearing gemstones as adornments, such as belts, bracelets, and necklaces, was common among early Christians, reflecting a belief in their protective and beneficial properties. While specific symbolism attributed to alexandrite is not explicitly detailed, its association with June and the corresponding zodiac signs (Gemini and Cancer) may carry certain astrological interpretations.
Care and Cleaning
Alexandrite’s relative hardness and toughness make it a durable gemstone suitable for various jewelry settings. However, proper care is essential to maintain its brilliance and protect its unique properties.
Cleaning alexandrite is best achieved with warm, soapy water and a soft brush. Ultrasonic and steam cleaners are generally considered safe, though caution is advised. It is important to avoid exposing the gem to high heat, as this could potentially cause damage. An alexandrite engagement ring, while a unique and beautiful choice, requires careful handling and regular cleaning to preserve its luster.
Conclusion
Alexandrite stands as a testament to the beauty and rarity found within the natural world. From its regal origins in the Ural Mountains of Russia to its modern status as a coveted June birthstone, this color-changing gem continues to captivate and inspire. Its unique geological formation, exceptional gemological properties, and historical significance combine to make alexandrite a truly remarkable and valuable gemstone.