When the sun shines, alexandrite is green. By candlelight, it’s red. How cool is that? Chatham crystals of alexandrite take months to grow. We’re thrilled to make this rare gem available for people like us who have always wanted one.MORE ABOUT ALEXANDRITES >>
Emerald by day. Ruby by night. Alexandrites are a rare variety of the mineral chrysoberyl that changes color from bluish-green in daylight or fluorescent light to brownish or purplish red in incandescent light.
Why do alexandrites change color? Alexandrites are colored by chromium, the amazing trace element that makes rubies red and emeralds green. In chrysoberyl, chromium causes a broad absorption band in the middle of the spectrum around 580 nanometers. That leaves two transmission windows, one in the red part of the spectrum, the other in the green. In light that is rich in red wavelengths, like incandescent light, candlelight or firelight, the gem appears red. In light that has more blue, like daylight or fluorescent light, the gem appears green. It’s science but it looks like magic!
Alexandrite was discovered in Russia’s Ural Mountains in 1830 and named after Czar Alexander II because its red and green colors matched the uniform of the Russian Imperial Guard. Those first alexandrites were of very fine quality, and displayed vivid hues and dramatic color change. Russian alexandrites are not mined today so fine mined stones are almost nonexistent except for in antique jewelry. That’s why alexandrites are so rare and valuable today.