Alexandrite
“Emerald by day, ruby by night”
Mineral
Alexandrite is a rare color-changing variety of the mineral chrysoberyl, prized as one of the most remarkable gemstones on Earth. It appears green in daylight and shifts to a reddish-purple under incandescent light due to the way chromium ions absorb different wavelengths.
Composition
chrysoberyl (BeAl₂O₄) with chromium impurities
Where Found
Ural Mountains (Russia — original source), Sri Lanka, Brazil, East Africa, India
Mohs Hardness
8.5
Fun Fact
Alexandrite was discovered in Russia in 1830 and named after Tsar Alexander II — its green and red colors conveniently matched the Russian imperial military colors.
Test Your Knowledge
Why is natural alexandrite considered rarer and often more valuable than diamond?
Related Specimens
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