ALEXANDRITE

Emerald by Day, Ruby by Night

alexandrite

1. What Is alexandrite?

It is a rare gemstone from the chrysoberyl family with the ability to change color depending on light. Fine alexandrites with a strong color change are extremely rare and can, in some cases, be more valuable than diamonds.

2. What color is alexandrite?

In natural daylight, it appears cool green or bluish-green, but under warm indoor light (like a lamp or candle), it shifts to red or purplish-red. This rare effect is why alexandrite is often called: Emerald by Day, Ruby by Night.

Alexandrite gemstone showing color change under different lighting
Alexandrite appears green in daylight and shifts to a reddish-purple under artificial light

3. What makes alexandrite change color?

This effect is caused by trace amounts of chromium within the crystal structure. Chromium absorbs and reflects different wavelengths of light, creating its unique color change. The human eye also plays a role, as our perception of color shifts depending on the light source. Greater contrast between green and red means higher value.

4. Where was it first found?

Alexandrite was discovered in the 1830s in Russia’s Ural Mountains. It was presented to the future Tsar Alexander II on his 16th birthday. The gemstone was named in his honor. It became a national treasure among Russian royalty and the tsars.

Alexander II

5. Why is Russian alexandrite so special?

Most of Russia’s original alexandrite supply was mined out in the 19th century, making genuine antique material extremely rare.  Its dramatic color change, combined with rarity and historical prestige, set the standard collectors still look for today.

ural-mountines
Alexandrite was first discovered in the Ural Mountains in Russia in the 1830s

6. Where is alexandrite found today?

Today, alexandrite is found in Sri Lanka, Madagascar, Myanmar (Burma), Tanzania, and Brazil. Brazilian stones often show a strong color shift but lighter tones, while Sri Lankan stones are valued for their clarity. African stones usually show fine green hues but are typically found in very small sizes.

Russian Alexandrite remains the most treasured

7. How is alexandrite cut?

Because alexandrite is a rare and often small gemstone, it is usually cut in ways that enhance its color change. Popular shapes like cushion, oval, and round are designed to retain weight while ensuring the stone’s shifting hues are shown to their best advantage.

8. Where is the world’s largest alexandrite?

One of the most famous examples of alexandrite is the world’s largest faceted stone, a 66-carat gem from Sri Lanka. It is housed in the Smithsonian Institution’s National Museum of Natural History in Washington, D.C.

Smithsonian Museum in Washington, DC. 
Smithsonian National Museum of Natural History in Washington D.C.

9. How hard is alexandrite?

Alexandrite is a strong and durable gemstone, ranking 8.5 on the Mohs scale of hardness.  It is the third hardest gemstone after diamond and corundum (the mineral family of sapphire and ruby.

10. Birthstone & Anniversary

Alexandrite is the official birthstone for the month of June. It is also the traditional gemstone used to celebrate a 55th wedding anniversary.

11. Refractive index

The refractive index measures how the gemstone bends light and influences how it appears to the eye. Alexandrite has a refractive index of 1.746 to 1.755, which contributes to its bright appearance and strong light reflection.

june
Alexandrite is the June birthstone

12. How to clean alexandrite?

To keep alexandrite looking its best, warm, soapy water is the safest choice.This simple care protects its surface and maintains its remarkable shine, ensuring the gemstone keeps its beauty for generations.

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📌 Alexandrite: Summary

  • Mineral: Chrysoberyl
  • Color: Green (daylight) to reddish-purple (warm light)
  • Discovered: In the 1830s in Russia’s Ural Mountains
  • Named after Tsar Alexander II
    of Russia
  • Mohs hardness: 8.5
  • Found in Sri Lanka, Brazil, and East Africa
  • Russian stones are the most prized
  • Largest faceted stone (66 ct) is in 
    the Smithsonian, Washington, D.C.
  • June birthstone
  • 55th wedding anniversary

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