Natural vs. Lab-Created Alexandrite: How to Tell the Difference (A Clarity & Inclusions Guide)

Alexandrite isn’t just another birthstone or color-shifting novelty. It’s one of those gems where rarity actually means something. Natural alexandrite—especially stones with a strong, clean color change—is incredibly hard to find. Lab-created alexandrite, meanwhile, is far more available and has become the version most people see online.

That gap between rare and readily available is where the confusion starts. You’ll see rings labeled “natural alexandrite” that look almost too perfect. You’ll see lab-grown stones that shift from green to purple like a light switch. And you’ll see a lot of listings that blur the details just enough to make you wonder what you’re really getting.

So the real question becomes simple: how can you tell natural and lab-created alexandrite apart?

This guide breaks everything down in a practical, grounded way—focusing on the three areas that matter most:

Inclusions
Clarity differences
Intensity and behavior of the color change

We’ll also walk through how to evaluate stones in person, what to look for in photographs, and which jewelers actually specialize in natural material, so you can check stones from reliable sources.

Let’s ease into it.

Why Natural and Lab Alexandrite Look Similar at First Glance

The reason this comparison is tricky is pretty straightforward: lab-created alexandrite isn’t fake. It’s chemically and structurally the same mineral—chrysoberyl—with the same chromium content that drives the signature color shift.

Nature formed its stones under chaotic geological pressure. Labs replicate those conditions with precision.

That’s why both can show:

Green or bluish-green daylight color
Red or purplish-red incandescent color
Strong color shifts
High clarity (though for different reasons)

The difference is in the details: the internal “fingerprints,” the clarity patterns, and how smooth or intense the color change looks.

Natural alexandrite carries the marks of its formation. Lab-grown alexandrite carries the signs of controlled growth. Once you know what those signs look like, the distinction becomes much clearer.

Inclusions: Nature Leaves Chaos, Labs Leave Patterns

If you only remember one concept from this article, make it this:
Natural alexandrite has organic-looking inclusions. Lab alexandrite has structured or highly uniform internal features.

Inclusions are the internal characteristics inside a gemstone—crystals, liquids, tiny fractures, growth marks, and other microscopic features.

Natural Alexandrite Inclusions

Natural stones often show “messy,” varied, irregular inclusions such as:

Needle-like rutile inclusions
Liquid fingerprints
Three-phase inclusions (liquid + gas + solid crystal in one cavity)
Angular, jagged growth zoning
Mineral crystals trapped during formation
Small feathering or natural “pinpoints”

The important part is the randomness. Nature never creates perfectly spaced lines or perfectly clear interiors in alexandrite. There’s almost always a clue hidden inside the stone.

Even high-quality natural alexandrite usually reveals something under 10x magnification.

Lab-Created Alexandrite Inclusions

Lab stones vary depending on the growth method (flux-grown or flame-fusion), but they commonly show:

Curved growth lines (a classic synthetic giveaway)
Parallel stripes or banding
Gas bubbles
“Plate-like” or metallic-looking flux inclusions
Highly consistent clarity across the entire stone

Flux-grown stones, which are the more convincing synthetics, often contain:

Shiny, reflective “platelets”
Stringy flux residue
Labile, organized patterns that don’t occur in natural material

If the inclusions look neat, patterned, or too organized, you’re likely looking at a synthetic.

Why jewelers rely heavily on inclusions

When labs like GIA or AGL evaluate alexandrite, inclusions are one of the first clues they look for. Natural stones almost always reveal their identity under magnification.

You—just using a jeweler’s loupe—can use the exact same approach.

Clarity: Natural Stones Almost Never Look Perfect

If you see a large alexandrite that’s flawlessly clear, pause for a moment. Natural alexandrite is almost never that clean. Even the finest stones tend to show minor inclusions, zoning, or internal texture.

Natural Alexandrite Clarity Tendencies

Slight to moderate inclusions are normal
Very high clarity is rare
Completely clean stones over 1 carat are extremely rare
Clean stones over 2–3 carats are almost unheard of

Natural stones often contain micro-area cloudiness or tiny crystal fingerprints. You should expect to see something going on inside the stone.

Lab-Created Alexandrite Clarity Tendencies

Lab stones often show:

High or exceptional clarity
Very few inclusions
Clean interiors even at larger sizes
Smooth internal structure

Because lab conditions are controlled, the stones simply don’t develop the same internal complexity you see in natural gems.

The “too good to be true” indicator

If a seller claims a stone is natural alexandrite but it’s:

Large
Flawless
Vibrant
And priced suspiciously low

…it’s almost certainly lab-created.

Color Change: Natural vs. Lab Differences (The Key Visual Clue)

The color-change effect is still the star of the show, and it’s one of the easiest ways to spot the difference—if you know what to look for.

Natural Alexandrite Color Change

Natural stones usually shift:

Green → mossy green → slightly bluish green in daylight
Reddish purple → warm raspberry → purplish red in incandescent light

The shift is real, sometimes dramatic, but rarely looks perfectly crisp. There’s nuance to it—undertones, soft transitions, subtle zoning.

The natural color feels alive and slightly unpredictable.

Lab-Created Alexandrite Color Change

Lab stones often flip:

Teal or blue-green → intense purple-red or neon red

The change is clean, uniform, highly saturated. It’s almost too perfect, which is a clue in itself.

Lab stones frequently show:

Stronger saturation
More pronounced contrast
A near-total shift across the entire stone
Smooth transitions with little zoning

The behavior of the shift matters

Natural alexandrite may show:

Uneven shift across different facets
Slight color mixing in transitional light
Areas where the green or red lingers
A shift that varies depending on the angle

Lab stones usually shift:

Evenly
Instantly
Without nuance

That difference is noticeable with just a bit of practice.

Lighting Tests You Can Do at Home

You don’t need specialized equipment to test alexandrite. In fact, three everyday light sources are enough.

Test 1: Daylight / Daylight LED

Natural stones often appear:

Slightly muted green
Mossy or bluish green
Not overly saturated

Lab stones often appear:

Blue-green
Teal
Highly saturated

Test 2: Incandescent Bulb (warm light)

Natural stones:

Turn raspberry or purplish-red
May show uneven or soft transitions

Lab stones:

Shift to strong red or red-purple
Look more uniform
Show higher saturation

Test 3: Fluorescent Light

Fluorescent lighting is where lab-made stones often look their most synthetic:

Many lab stones appear bluish or cool-toned
Natural stones remain greener or slightly duller

Why Color Zoning Helps Identify Natural Material

Color zoning refers to areas of slightly different color inside the stone.

Natural stones commonly show:

Patches of lighter or darker green
Areas where the red or purple shift is weaker
Directional zoning from crystal growth

Lab stones, with their engineered composition, rarely show significant zoning. Their color tends to be:

Even
Predictable
Smooth across the entire stone

If the stone looks uniform from edge to edge, it’s more likely synthetic.

Stone Size: Another Hidden Clue

Natural alexandrite over 1 carat is rare. Stones over 2 carats are very rare. Stones over 5 carats are basically museum-grade.

Lab stones are easy to grow in large sizes.

So if you see:

A 3–4 carat alexandrite ring
Bright clarity
Strong color shift
A surprisingly accessible price

…it’s almost certainly lab-created.

Size alone doesn’t determine origin, but it should always make you investigate more closely.

**Where Natural Alexandrite Is Actually Sold**

Most natural alexandrite online is mislabeled—sometimes intentionally, sometimes because sellers don’t know the difference themselves.

That’s why it helps to look at jewelers who specialize in natural or certified stones. While you can’t link directly to specific stones here, you can point readers toward reputable categories:

Jewelers Known for Natural Alexandrite

These jewelers regularly carry certified natural stones and have inventory that reflects the real-world scarcity:

Leibish & Co. – Known for certified natural alexandrite with color-change videos.
Brilliant Earth (Natural Collection) – Offers responsibly sourced natural gems with GIA and AGL reports.
The Natural Sapphire Company – Despite the name, they carry natural alexandrite with detailed imaging.
GIA-Certified Stone Retailers – Any seller that provides independent lab reports from GIA, AGL, or GRS is a safer bet.

Browsing these sources is a helpful baseline. Once you see what real natural alexandrite looks like, the differences become easier to spot everywhere else.

Flux vs. Flame-Fusion: How Lab Stones Reveal Their Origin

Different lab methods leave different signatures.

Flame-Fusion (Verneuil) Alexandrite

These are the easiest synthetics to spot:

Curved growth lines
Gas bubbles
Strong blue-green to red-purple shifts

They often look “electric.”

Flux-Grown Alexandrite

These are more convincing but still show:

Metallic-looking flux inclusions
Slight plate-like structures
Higher clarity
Strong, predictable color change

Even flux stones, which can fool an untrained eye, leave their fingerprints under magnification.

A Practical Step-by-Step Review Process

Here’s a streamlined approach you can use anytime you evaluate alexandrite.

1. Start with the color change

Ask yourself:

Does it look too perfect?
Is the green too blue?
Is the red too neon?
Does the shift look uniform?

2. Move to clarity

Check for:

Natural inclusions (needles, fingerprints, crystals)
Synthetic patterns (curved lines, bubbles)

3. Check size vs. clarity

Large + flawless almost always means lab-grown.

4. Examine color zoning

Natural → slight unevenness is normal
Lab → even saturation is common

5. Consider the setting

Natural stones are almost always mounted in:

Gold
Platinum

Mass-market silver settings almost always contain lab stones or imitators.

6. Look for certification

If it’s truly natural, sellers will want to show:

GIA report
AGL report
GRS report
Detailed inclusion photography

If a seller avoids these, the stone isn’t natural.

Common Misrepresentations to Watch Out For

Online listings can be vague in ways that feel intentional. Watch for phrases like:

“Alexandrite-like”
“Color-change stone”
“Synthetic alexandrite but described as genuine”
“Lab alexandrite treated to resemble natural”
“Stones from Siberian mines” (almost always unverified)

And the big one:

“Natural alexandrite” with no certificate or independent verification.

Natural alexandrite is so rare that any seller offering it without documentation should be treated cautiously.

Why Many Buyers Choose Lab-Created Alexandrite Anyway

Natural stones offer rarity and character. Lab stones offer color consistency and accessibility. There’s no wrong choice here—just different goals.

Natural Alexandrite Gives You:

Authentic rarity
Organic inclusions
Complex, nuanced color change
Collector and resale value

Lab-Created Alexandrite Gives You:

Intense, dramatic color shifts
Clean clarity
Larger sizes
Lower cost

It’s not a matter of “real vs. fake.” It’s a matter of choosing the version that matches what you value most.

Conclusion: The Details Tell the Story

Natural alexandrite and lab-created alexandrite might look similar in a picture, but the differences show up in the details if you slow down and actually observe the stone.

Natural stones carry the distinctive, unpredictable fingerprints of geology. Their inclusions are organic. Their color change is complex. Their clarity is never flawless. Their personality is unmistakable.

Lab stones carry the precision of engineered growth. Their color is strong. Their interiors are clean. Their transitions are smooth. Their appearance is consistent.

If you know how to interpret the patterns—inclusions, clarity, color behavior—you can tell them apart with confidence. And if you want to check your instincts against reliable benchmarks, jewelers who specialize in certified natural material give you a reference point you can trust.

Whether you end up choosing natural or lab-created alexandrite, the key is understanding what you’re looking at. Once you see how these stones express themselves, the differences aren’t subtle at all.