Alexandrite | Chrysoberyl-Color Change Variety

Alexandrite :

If the idea of magic captivates you, few gems can rival the enchantment of alexandrite. Known for its extraordinary ability to change color depending on the light source, this gemstone can appear as a rich, bluish-green in daylight or fluorescent lighting, then shift dramatically to a vibrant raspberry red under candlelight or incandescent bulbs. This captivating transformation has long inspired poets, who coined the phrase: “Emerald by day, ruby by night.”

This remarkable optical shift—so distinct it’s been dubbed “The Alexandrite Effect”—can be instantly observed by switching between different light sources. While some gemstones show subtle color changes, alexandrite’s transformation is uniquely vivid and mesmerizing.

A rare variety of chrysoberyl (BeAl₂O₄), alexandrite owes its magic to trace amounts of chromium, with additional elements like iron and titanium contributing to its color dynamics. These elements filter light in such a way that the gem transmits either green or red hues, depending on the dominant wavelength of the surrounding light.

Discovered in the 1830s in Russia’s Ural Mountains, alexandrite was named in honor of the future Tsar Alexander II—its red and green hues mirroring the colors of Imperial Russia. Though the original Russian deposits produced some of the most exquisite specimens ever found, they were quickly depleted. Today, alexandrite is mined in Brazil, Sri Lanka, India, and parts of East Africa. Brazilian stones are considered the closest in quality to the revered Russian originals, while Sri Lankan specimens often exhibit a subtle brownish undertone.

At the time of its discovery, electric light didn't exist, so the gem’s red glow was revealed only in the warmth of candlelight—adding to its mystical allure. Recreating this effect today often requires an open flame, as modern LED lighting lacks the right spectrum to trigger the full transformation.

With a hardness of 8.5 on the Mohs scale, excellent toughness, and no cleavage, alexandrite is both durable and suitable for everyday jewelry. It is also pleochroic, displaying different colors—green, yellow-orange, and red-purple—when viewed from different angles, a feature skilled gem cutters use to maximize its visual impact.

Sharing June’s birthstone status with pearls, alexandrite is one of the rarest and most valuable gemstones in the world. Fine-quality stones over one carat are incredibly scarce, making alexandrite not only a gem of beauty and mystery but also of true rarity and prestige.