How to Tell if an Alexandrite Is Real
Real alexandrite is so rare that most 'alexandrite' jewelry — especially vintage pieces — is actually synthetic color-change sapphire. The test that matters is the quality of the color change: true alexandrite swings green-to-red, while the common fakes swing blue-to-purple. Price is the other tell: genuine alexandrite has no bargains.
The 60-Second Alexandrite Checklist
Run these quick checks first — most fakes fail at least one before you ever reach for a loupe.
- Green/teal in daylight → red/raspberry under incandescent light
- Blue-to-purple change = synthetic color-change sapphire
- Strong pleochroism: green, orange, purple-red down different axes
- Real alexandrite over 1 ct starts at five figures — cheap means fake
- Most 'grandma's alexandrite' from 1900–1980 is synthetic sapphire
5 At-Home Tests for Real Alexandrite
Work through these in order — each one is safe for genuine alexandrite unless noted, and together they expose nearly every common fake.
The two-lamp color-change test
View the stone under cool daylight/LED (5000K+), then under a warm incandescent or candle-type bulb. Phone flashlights are too white — use a genuinely warm source like a halogen or candle-type bulb.
Real alexandrite
Alexandrite shifts from green/bluish-green to red/purplish-red — the famous 'emerald by day, ruby by night'. Fine stones shift 80–100% of their body color.
Fake
Synthetic color-change sapphire (the classic impostor) shifts grayish-blue to purple/mauve — never a true green-to-red swing.
Daylight hue inspection
Judge the daylight color carefully against known references.
Real alexandrite
Bluish-green to teal-green body color in daylight.
Fake
If the 'daylight' color is blue-gray or violet-blue, you're looking at sapphire chemistry, not chrysoberyl.
Pleochroism check
Rotate the stone down different axes in daylight.
Real alexandrite
Alexandrite is strongly trichroic: green, orange-yellow, and purple-red appear down different directions.
Fake
Color-change glass shows nothing; synthetic sapphire shows weaker two-color shifts.
Loupe for curved striae and bubbles
Examine the interior at 10× under side light.
Real alexandrite
Natural alexandrite may show fine needles, fingerprints, or step-like growth zoning.
Fake
Curved growth lines and tiny gas bubbles betray Verneuil synthetic sapphire; perfect emptiness in a large stone suggests lab-grown material of either kind.
Price and provenance sanity check
Compare the ask against the real market before believing any story.
Real alexandrite
Natural alexandrite with a good change runs $1,000–$70,000+ per carat; 1 ct+ fine stones are five-figure gems.
Fake
A '3-carat alexandrite' for $200 is synthetic — no exceptions, no estate-sale miracles.
Common Fake Alexandrites & How to Spot Them
These are the materials most often sold as alexandrite — and the giveaway that exposes each one.
| Imitation | How to spot it | The giveaway |
|---|---|---|
| Synthetic color-change sapphire | Blue-to-purple change, curved striae, often in vintage jewelry sold as 'alexandrite'. | Wrong colors in both lights — no true green, no true red. |
| Lab-grown alexandrite | Real chrysoberyl chemistry with excellent change, but too clean and 'too good' for the price. | Genuine material worth ~$100–500/ct — fine if disclosed, fraud if sold as natural. |
| Color-change garnet | Shifts bronze-green to raspberry; singly refractive, no trichroism. | A lovely natural gem, but the shift starts from brownish-green, not alexandrite's teal. |
| Andalusite (misidentification) | Shows green and red simultaneously from different facets rather than changing with light source. | Pleochroism mimicking color change — rotate it under one light to expose the difference. |
When to get professional testing
No colored stone needs lab paper more than alexandrite. Natural-vs-synthetic and Russia/Brazil/Sri Lanka origin calls can swing value by 100×, and the synthetic sapphire impostor fools most consumers. GIA, Gübelin, or AGL certification is mandatory at these prices — budget it into any purchase.
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Real vs Fake Alexandrite: Your Questions
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Statistically, probably not. From roughly 1900–1980, enormous quantities of synthetic color-change sapphire were sold worldwide as 'alexandrite', especially in rings from Mexico, Egypt, and mail-order catalogs. If it shifts blue-to-purple rather than green-to-red, it's the sapphire impostor — still a nice stone, worth perhaps $50–100.
Teal-to-bluish-green under daylight swinging to red, raspberry, or purplish-red under incandescent light. Quality is graded by the completeness of the shift — fine stones change 80–100% of their face-up color. Weak, partial, or blue-purple shifts mean lesser stones or different materials.
Among the highest per-carat prices of any gem: roughly $1,000–$5,000/ct for small or weak-change stones, $5,000–$25,000/ct for fine 1 ct stones, and $30,000–$70,000+/ct for fine Russians and large gems with dramatic change. Lab-grown alexandrite, by contrast, runs a few hundred dollars per carat.
It's genuine chrysoberyl with a genuine color change — legitimate when disclosed and a defensible way to own the phenomenon for ~1% of natural prices. It becomes fraud only when sold as natural, which is why certification matters at every price point for this gem.
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Home tests are screening tools, not certification. For high-value purchases, insurance, or resale, confirm with an accredited gem lab (GIA, AGL, Gübelin, SSEF).