10 Fascinating Facts About Alexandrite

Alexandrite is one of the most intriguing and elusive gemstones in the world. Best known for its remarkable ability to change colour, this rare stone has captured imaginations since the moment it was discovered.

Often referred to as “emerald by day, ruby by night,” alexandrite is prized by collectors, gem lovers, and jewellers alike. From imperial connections to record-breaking specimens, here are ten fascinating facts about this chameleon-like gem.

Alexandrite Changes Colour in Different Light

The most iconic feature of alexandrite is its dramatic colour change, from greenish in daylight to reddish under incandescent light. This phenomenon occurs due to the presence of chromium in the gem’s crystal structure, which causes complex light absorption in the visible spectrum.

It’s Also Pleochroic (So the Colour Change Isn’t Just About Light)

In addition to changing under different lighting, alexandrite is pleochroic, meaning it can show multiple colours when viewed from different angles. This adds an extra layer of optical magic to an already mesmerising stone.

Truly Fine Colour Change is Incredibly Rare

Not all alexandrite is created equal. Only about 5% of all mined alexandrite displays a strong, vivid colour shift from green to red with high contrast. These top-tier gems are the most valuable and sought-after by collectors.

Alexandrite Is Over 100,000 Times Rarer Than Diamond

Annual global production of natural alexandrite is estimated to be under 1,000 carats. For comparison, over 130 million carats of diamonds are mined each year. 
Stones over 5 carats with fine colour change are particularly scarce. Fewer than 10 are estimated to be found annually.

Its Price Per Carat Can Surpass Ruby and Emerald

Because of its extreme rarity and visual uniqueness, fine-quality alexandrite often sells for more per carat than diamonds, rubies, or emeralds. This makes it not just a beautiful choice, but also a potential collector’s investment.

The World’s Largest Faceted Alexandrite Weighs 141.92 Carats

The largest known faceted alexandrite weighs a staggering 141.92 carats and is privately held in Japan. This extraordinary gem is valued at over $100 million and showcases the incredible size and clarity that alexandrite can achieve, albeit very rarely.

Alexandrite Was First Discovered in Russia and Became a National Symbol

Alexandrite was discovered in the Ural Mountains of Russia in the 1830s. Its striking red and green hues mirrored the colours of the Imperial Russian military, and it was quickly adopted as a patriotic symbol. It even became the official national stone of Russia.

Alexandrite Vanished for Decades

After the Russian deposits were depleted in the early 20th century, natural alexandrite all but disappeared from the market. It wasn’t until the 1980s that new sources were discovered in countries like Brazil, Sri Lanka, and Tanzania. But even today, mining yields remain extremely low, often just a few grams per tonne of ore.

Most Chain Store Alexandrite Jewellery Isn’t Natural

Due to its cost and scarcity, natural alexandrite is almost never seen in mainstream jewellery retailers. Instead, these pieces typically feature synthetic alexandrite or lookalike stones like colour-change sapphire or spinel.

In Victorian Times, It Was Thought to Predict Mood and Fate

Victorian gem enthusiasts were captivated by alexandrite’s ability to change colour. Some believed it could reflect your emotional state or even warn of misfortune. This added to the stone’s mystique and popularity during the 19th century, especially among the upper class.

From imperial ties to optical tricks, alexandrite is more than just a pretty face, it’s a gemstone steeped in rarity, science, and story. Whether you're a collector, a jeweller, or simply a lover of the unusual, alexandrite is a gem that never ceases to amaze.