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Chrysoberyl · BeAl₂O₄ + Cr · 8.5

Alexandrite

Alexandrite is chrysoberyl coloured by a trace of chromium, and it changes colour: green or teal in daylight, red to purple under warm lamplight. Fine mined alexandrite is one of the rarest and most expensive gems. Real lab alexandrite is the same mineral, grown slowly, and costs tens to a couple of hundred dollars a carat. Most cheap "alexandrite" on Amazon is something else: colour-change sapphire, glass or CZ.

From the ground to your hand

The same stone at four moments. Tap a photo of a listing to see it on Amazon.

  1. 01 In the ground (step 1 of 4)

    An alexandrite crystal from the Ural Mountains of Russia, in daylight. It was first found in the Urals emerald mines in the 1830s.

    An alexandrite crystal from the Ural Mountains of Russia, in daylight. It was first found in the Urals emerald mines in the 1830s.

    Real specimen. Photo: Lech Darski, CC BY-SA 4.0.

  2. 02 The colour change (step 2 of 4)

    The same 26.75 ct stone twice: bluish green in daylight, purple-red under an incandescent bulb. Mined alexandrite this large is extremely rare.

    The same 26.75 ct stone twice: bluish green in daylight, purple-red under an incandescent bulb. Mined alexandrite this large is extremely rare.

    Real specimen. Photo: Wikimedia Commons (original uploader), CC BY-SA 3.0.

  3. 03 Out of the lab (step 3 of 4)

    A lab alexandrite of about 19 to 20 ct, 18 x 13 mm, the biggest we found. Lab alexandrite is grown from a melt or a flux over days to months.

    A lab alexandrite of about 19 to 20 ct, 18 x 13 mm, the biggest we found. Lab alexandrite is grown from a melt or a flux over days to months.

    Amazon listing photo. See it on Amazon

  4. 04 Set (step 4 of 4)

    Lab alexandrite studs in 14K white gold, 2 ct total, from PEORA.

    Lab alexandrite studs in 14K white gold, 2 ct total, from PEORA.

    Amazon listing photo. See it on Amazon

Mineral
Chrysoberyl (beryllium aluminium oxide)
Colour from
Chromium
Hardness
8.5 on the Mohs scale
Grown in labs since
The 1970s (flux and pulled crystals)
Famous sources
Urals (historic), Sri Lanka, Brazil, East Africa

Famous alexandrite in museums

What the finest natural stones look like: real pieces in public collections. The whole gem museum.

The Maharani Cat’s Eye: A chrysoberyl cat’s eye of 58.2 carats from Sri Lanka: the same mineral as alexandrite, with a silky band of light across it.
The Maharani Cat’s EyeA chrysoberyl cat’s eye of 58.2 carats from Sri Lanka: the same mineral as alexandrite, with a silky band of light across it.Smithsonian National Museum of Natural History, WashingtonChrysoberyl has two famous forms: alexandrite, which changes colour, and cat’s eye, whose fine needles make a sliding line of light.Photo: thisisbossi from Washington, DC, USA, CC BY-SA 2.0.

Mined vs lab-grown alexandrite

Mined and lab-grown alexandrite are the same mineral; this is what differs
MinedLab-grown
How it formedWhere beryllium-rich granite met chromium-rich rock, a rare meetingPulled from a melt (Czochralski), floated zone, or flux, over days to months
Colour changeOften partial; strong, clean change is rare and prizedUsually strong and dependable
InsideSilk, fingerprints, twinningClean, or flux veils in flux-grown stones
PriceThousands to tens of thousands of dollars a carat for good changeRoughly $35 to $230 a carat on Amazon
ResaleFine stones hold valueLittle

Price is the first test. Real lab alexandrite on Amazon costs roughly $35 to $230 a carat in our checks; mined alexandrite with a good change costs far more. A "100 ct natural alexandrite pendant" for $30, or a "colour change alexandrite" ring with a big stone for under $100, is not alexandrite.

Treatments. Alexandrite is rarely treated. The problem is identity, not treatment: colour-change synthetic sapphire ( doped with vanadium) has been sold as "alexandrite" for about a century, and so have colour-change glass and CZ. A report is worth it on any expensive stone. All gem treatments explained.

Where natural alexandrite comes from

Pins mark mining districts, not exact mines. Drag to move, pinch or scroll to zoom, tap a pin to read about it. Map data © OpenStreetMap contributors.

List of every place on the map (4)
  • Alexandrite: Malysheva (Tokovaya) emerald mines, Urals, Russia. Where alexandrite was first found, in the 1830s. The classic source of strong green-to-red stones; little is mined now.
  • Alexandrite: Ratnapura and gem gravels, Sri Lanka. Alexandrite and cat’s-eye chrysoberyl from river gravels, sometimes in large sizes.
  • Alexandrite: Hematita, Minas Gerais, Brazil. A 1987 find that produced some of the finest alexandrite of modern times.
  • Alexandrite: Tunduru, Tanzania. Gem gravels that yield alexandrite with sapphire and spinel.

How it is cut

Lab alexandrite is mostly machine-cut in calibrated sizes, which is why a cut lab stone costs little more than its rough. Fine mined stones are often native-cut to keep weight, then recut by precision cutters. See cuts from easiest to hardest and whether cutting your own is cheaper than buying cut.

What to buy

Checked in stock on October 10, 2026. Photos are the listings' own; prices are rounded.

All checked lab alexandriteWhich gems can be lab-grownReading a gem listing

The alexandrite shop: 31 more pieces we trust

Every piece names the real stone and comes from a seller with a record, checked in stock on October 11, 2026. Photos are the listings' own; prices are rounded.

WomenChatham created alexandrite studs, 4 mm, 14K white gold (via Trustmark)Chatham flux-grown alexandrite.about $290on Amazon →Women0.5 ctChatham created alexandrite studs, 4 mm, 0.5 ct total, 14K yellow goldFull colour change. Ships on a lead time.about $650on Amazon →WomenPEORA lab alexandrite and diamond heart pendant, 6 mm, 14K white goldOver 150 ratings. Ships on a lead time.about $280on Amazon →Loose stones9 to 15.5 ctInstagem lab alexandrite, oval, 16 x 12 mm, 9 to 15.5 ctA very big lab alexandrite.about $1,150on Amazon →Loose stonesInstagem lab alexandrite, pear, 16 x 12 mmBig pear, priced like real lab alexandrite.about $1,000on Amazon →Jewellery2.5 ctLab alexandrite earrings, 6 mm, 2.5 ct, 14K white goldabout $350on Amazon →Jewellery2.5 ctLab alexandrite pendant, round, 8 mm, 14K white gold, 2.5 ctabout $280on Amazon →JewelleryLab alexandrite earrings, 14K yellow goldabout $350on Amazon →Jewellery1.25 ctLab alexandrite pendant, cushion, 6 mm, 14K white gold, 1.25 ctabout $250on Amazon →Jewellery3 ctLab alexandrite pendant, princess, 8 mm, 14K white gold, 3 ctabout $280on Amazon →Loose stones18.89 to 20.08 ctLab alexandrite, 18 x 13 mm, 18.89 to 20.08 ctabout $1,850on Amazon →Loose stones9.9 to 10.05 ctLab alexandrite, 10 x 8 mm, 9.9 to 10.05 ct the pairabout $340on Amazon →

See all 44 in the lab gem catalog

Your kit for alexandrite

Five tools that let you check what you bought (a loupe, a UV torch, locking tweezers, a gem box and a pocket scale), plus a turntable that spins your stone under the light the way jewellers show one. The full collector's kit.

LookGemOro 10x triplet loupeunder $20LookDARKBEAM filtered 365 nm UV flashlightabout $10HandleHonoson locking tweezers, 3 packabout $10StoreTeensery gem display boxes with clear lids, 10 packabout $9ShowComXim motorized turntable, adjustable speed and directionabout $15MeasureGemOro Platinum XP500 pocket scale, 0.01 gabout $40

In short

Alexandrite grows over millions of years in the earth, or in hours to months in a lab. Both are real alexandrite; the mined stone is rare and priced for rarity, the lab stone is priced for the cost of growing it. Buy lab to wear and enjoy, check the listing names the mineral, and test it when it arrives.

See our first pick: PEORA lab alexandrite stud earrings, 2 ct total, 14K white gold

Frequently Asked Questions

Is lab alexandrite real alexandrite?

Yes, if it is lab-grown chrysoberyl. It has the same chemistry, hardness and colour change as mined alexandrite. The trouble is that much of what is sold as "lab alexandrite" or "colour change alexandrite" is synthetic sapphire, glass or CZ.

How can I tell fake alexandrite from real?

Start with price: real lab alexandrite costs tens of dollars a carat or more, so a big, very cheap stone is not it. Colour-change sapphire usually shifts blue-violet to purple, not green to red. Watch a video of the stone moving between daylight and a warm bulb, and for anything expensive ask for a lab report that names chrysoberyl.

Why is alexandrite named after a tsar?

It was found in the Ural emerald mines in the 1830s and named after the future Tsar Alexander II. Its red and green matched the colours of imperial Russia.

Is alexandrite good for a ring?

Very. At 8.5 on the Mohs scale, tough and without easy cleavage, it wears better than emerald and nearly as well as sapphire.

Photo credits

  • alexandrite-crystal-urals.webp: Lech Darski, CC BY-SA 4.0, via Wikimedia Commons.
  • alexandrite-colour-change.webp: Wikimedia Commons (original uploader), CC BY-SA 3.0, via Wikimedia Commons.
  • Product photos: Amazon listings, via the Amazon Product Advertising (Creators) API.

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