A relatively modern gemstone, alexandrite was discovered in Russian emerald mines located in the Ural Mountains. Legends claim that it was discovered in 1834 on the same day that future Russian Czar Alexander II came of age, and was named to honor him.
Often described as “emerald by day, ruby by night,” alexandrite is a rare variety of the mineral chrysoberyl that changes color from bluish green in daylight to purplish red under incandescent light.
This chameleon-like color shift is the result of its uncommon chemical composition which includes traces of chromium, the same coloring agent found in emerald. The unlikelihood of these elements combining under the right conditions makes alexandrite one of the rarest and most expensive gemstones on earth.
The alexandrite mined from Russia’s famed deposits set the quality standard for this gemstone. Today most alexandrite comes from Sri Lanka, Brazil, and East Africa generally paling in comparison to the vivid colors of Russian gemstones.
With a hardness of 8.5 on the Mohs scale, alexandrite is softer than sapphire and harder than garnet—the other gemstones that can change color. However, due to its scarcity, alexandrite is more valuable than most gemstones, even rubies and diamonds.
Associated with concentration and learning, alexandrite is believed to strengthen intuition, aid creativity and inspire imagination, bringing good omens to anyone who wears it.
Alexandrite - June's Modern Birthstone
While pearl may be the most famous of June's birthstone, Alexandrite is the most modern and has a color changing feature that is rarely seen in any other stone. This unique ability and the rarity of this stone defines the birthstone, which has been said to strengthen intuition, aid creativity and expand the imagination.
Alexandrite's Unique Ability
This 'chrysoberyl' birthstone and it's chameleon-like ability to change colors have been astounding to many since it was first found in Russia in 1831. The stone appears to be either a sea-foam green or blueish color in daylight, but when put under incandescent light (like your light bulb - electric light), it changes to a purplish or red/pink color. This can be seen because of the "spectrum of color" that incandescent light shows versus others and it is absorbed and reflected differently in Alexandrite.
Why does Alexandrite Change Color?
We would love to have an easy explanation for the color change, but as you'd might expect, it is much more in-depth than that. As we stated above, the reasoning is because the birthstones chemical structure and absorbs and reflects light differently.
To get a bit more background on the Alexandrite, it is a trichroic gemstone meaning it has 3 different and distinct optical directions. This allows for different colors to be seen from different directions of viewing the stone. Although this does not explain the color change it helps to give us an understanding on how the gem can have multiple 'colors' in the same light at times. The color change is a result of having chromium +3 ions in it's chemical structure and how they reflect and absorb light.
In short, the chromium level that is found in alexandrite is balanced right between the levels in both ruby and emerald. This gives the stone the reddish ruby colors when in incandescent light, and the green emerald colors when in natural light.