Alexandrite: The Chameleon of Gemstones
Alexandrite, a rare and enchanting color-changing variant of chrysoberyl, holds the honor of being June’s birthstone. Its discovery traces back to 1830 in Russia, coinciding with the coming-of-age celebration of Czar Alexander II, after whom the gem was named. Its most captivating feature is its ability to shift colors — from a lush green in daylight to a deep red under incandescent lighting, earning it the poetic description: “emerald by day, ruby by night.” To witness this mesmerizing transformation, simply observe the stone under both daylight and incandescent illumination.
The value of an alexandrite gem escalates with the intensity of its color change. Some specimens exhibit a dramatic 100% shift, while others might display a subtle 5% variation. In natural light, its spectrum spans from a pronounced bluish-green to a yellowish-green, whereas under incandescent light, it radiates hues from orangy-red to purple-red.
Historically, Russia’s mountains were the primary source of the world’s most sought-after alexandrite. However, their yield has dwindled over time. Brazil also boasts deposits, but access to these mines is currently restricted by the government. Sri Lankan alexandrite, while available, often presents a minimal color change, discernible mainly under lab conditions.
Properties and Alternatives
With a hardness of 8.5 on the Mohs scale, alexandrite is a resilient gem. It remains untreated, preserving its natural allure. For those seeking a more affordable alternative to the genuine gem, lab-created chrysoberyl offers a comparable composition and properties. While these lab-grown variants share the same essence, other substitutes like lab-created sapphire (alexandrite corundum) and color-changing cubic zirconia, though visually similar, don’t capture the true essence of alexandrite. Colored glass is another available option, but it lacks the depth and authenticity of the original gem.