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Emerald by Day, Ruby by Night: Color-Shifting Alexandrite

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Shifting from striking blue-green in sunlight to soft purplish-red under artificial light, the outstanding alexandrite is a gemstone like no other. 

Taking its name from Russia's Alexander II — the Tsar who freed Russia’s serfs in the 1800s — this young gem is unusually rare, and its remarkable shifts in color make it one of the most valuable gemstones of all.

Spectacular Rarity

Alexandrite is a precious form of chrysoberyl, a type of crystal that forms from slowly cooling magma in the earth's crust. As magma moves upwards from the earth's molten core, it picks up trace elements along its journey.

While all stones in the chrysoberyl family are composed primarily of aluminum and beryllium, it's the additional presence of trace amounts of chromium that gives alexandrite its seemingly miraculous color-changing beauty. Its extreme rarity is likewise owed to this unlikely composition.

A Chromium Chameleon

The chromium in alexandrite is responsible for its unique color-shifting as it absorbs visible light in the yellow and blue part of the color spectrum, but reflects red and green light to varying degrees.

When viewed under natural daylight, which contains all the color wavelengths in the visible light spectrum, alexandrite reflects green light strongly and red weakly, giving the gem a blue-green appearance.

Artificial light sources like incandescent lights are focused primarily in the warmer end of the visible light spectrum, so without green wavelengths, the red in the gem shines through as a garnet-like purplish-red hue.

While other gems exhibit similar shifts in color, none do so as dramatically as alexandrite, and these shifts have come to be known as the "alexandrite effect."


(images source: GIA)

Hiding in Plain Sight

I find it so exciting that we are living at the perfect moment to appreciate alexandrite truly.

While the gems themselves take eons to form, we think of alexandrite as a "young" gem due to the relatively recent discovery of its color-shifting abilities. Without artificial light, only half of an alexandrites astounding beauty may be revealed!

A Thoroughly Modern Stone

Alexandrite was first discovered in the 19th century, so it lacks the ancient lore that accompanies most gems. However, what it lacks in age it makes up for in intrigue.

Alexandrite was first discovered in the 1830s in the Ural Mountains of Russia. As the story goes, an emerald miner collected some stones that he took to be emeralds. When viewed later that night, however, they shone a bright red. The following morning, when the gems once again appeared green, he was shocked and knew he had stumbled onto something quite special.

Fit for a King (or a Tsar)

These first alexandrite deposits discovered were characterized by vivid colors, and their green and red tones captured the imagination of imperial Russia as they mirrored the national military colors. Legend has it that this discovery took place on the same day that Tsar Prince Alexander II came of age, and so alexandrite was later named in his honor.

While the gem was quite popular with Russian aristocracy, it was America's George Kunz — Tiffany’s master gemologist — who popularized the gem more globally during the late 19th and early 20th centuries. He was captivated by alexandrite’s unique properties and loved the stone so much he crafted an assortment of pieces displaying the rare gem in platinum settings. Most fine Alexandrite’s today originate from Brazil and they are in very limited supply.

Timely and Timeless

There has never been a better time to appreciate alexandrite. If it has captured your imagination as it has mine, please reach out today. I'd love to share my passion for this stone and help you invest in the perfect piece of timeless, wearable art that you'll treasure always.