Lab-Grown Emeralds

What Is a Lab-Grown Emerald?

A lab-grown emerald is beryl colored by chromium, with the same mineral composition, coloring agents, and crystal structure as a natural emerald mined from the earth.

The chemical formula is identical: Be₃Al₂Si₆O₁₈ with trace chromium (and sometimes vanadium) producing the green.

It has the same hardness of 7.5 to 8 on the Mohs scale and the same refractive index of 1.57 to 1.58 as natural emeralds.

Under a gemological microscope, the crystal is beryl. Under a spectrometer, the chromium signature is the same.

The primary difference between natural and lab-grown emeralds is where the gemstone forms.

Natural emeralds form over millions of years in hydrothermal veins deep in the Earth's crust, where beryllium, aluminum, silicon, and chromium converge under extreme heat and pressure.

Lab-grown emeralds recreate these natural growth conditions in a controlled environment, producing genuine emeralds within weeks or months instead of millions of years.

The result is the same mineral, grown faster, in a controlled environment, without the geological conditions that often create fractures, inclusions, and the need for oil treatment.

Lab-grown emeralds are not simulants, imitations, or green alternatives made from different materials. They are real emeralds with the same chemical and physical properties as natural stones.

They are not glass. They are not cubic zirconia dyed green.

The difference is in origin. Lab-grown emeralds do not have a geological formation history, but they offer clarity, consistency, and a more accessible price point for buyers exploring emerald jewelry.

The 99% Truth: Why Natural Emeralds Need Oil

This is a detail many buyers do not learn before purchasing natural emerald jewelry.

Approximately 99% of natural emeralds receive oil or resin treatments to improve clarity and reduce the visibility of surface-reaching fractures.

The treatment involves filling fractures with cedar oil, synthetic oil, or polymer resin (such as Opticon) to make the stone appear cleaner and more transparent.

The oiling is not permanent.

Over time, heat, ultrasonic cleaning, or harsh chemicals can affect these treatments. This may cause fractures to become more visible and require additional care.

This is standard maintenance for many natural emerald pieces.

Many buyers researching lab-grown emeralds are surprised to learn that untreated natural emeralds are extremely rare.

Lab-grown emeralds do not need oil.

Because they grow in a controlled environment, they typically develop fewer fractures and inclusions than many natural stones.

This means the clarity you see in a lab-grown emerald is generally the clarity you receive, without relying on oil or resin treatments to improve appearance.

No oil. No resin. No maintenance schedule.

For customers looking for lab-grown emerald jewelry, this provides a straightforward alternative with transparent characteristics.

This doesn't make natural emeralds inferior.

The "jardin" (French for "garden") of inclusions in a fine natural emerald is genuinely beautiful and valued by collectors.

However, buyers who prefer a cleaner appearance and fewer treatment concerns often choose lab-grown emeralds as an alternative.

How Lab-Grown Emeralds Are Made

Hydrothermal Growth

The hydrothermal method replicates the conditions under which natural emeralds form.

This process recreates the high-pressure, high-temperature environment that allows emerald crystals to grow naturally beneath the earth.

Raw materials (beryllium oxide, aluminum oxide, silica, and chromium oxide) are placed in a sealed high-pressure chamber called an autoclave.

Water is added.

The chamber is heated to 600 to 800°C at pressures of 700 to 2,000 bars.

Inside the chamber, minerals dissolve in superheated water and slowly recrystallize onto a seed plate of colorless beryl, forming a genuine emerald crystal.

Hydrothermal emeralds grow in weeks rather than months.

They often produce lab-grown emerald gemstones with exceptional clarity and vivid, saturated color.

Under magnification, they may show growth tubes, nail-head spicules, and chevron patterns that are characteristic of this method.

These characteristics are not flaws. They are growth patterns that reveal how the emerald was created.

Flux Growth

The flux method dissolves raw ingredients in a molten chemical solvent known as a "flux," typically lithium molybdate or similar materials.

As the mixture slowly cools over weeks to months, emerald crystals form on a seed.

Flux-grown emeralds often develop inclusions that resemble natural emerald characteristics, making them highly valued among collectors and gemstone enthusiasts.

Flux growth is slower and more expensive than hydrothermal growth.

The slower process allows flux-grown emeralds to develop a more natural appearance, with internal features that can closely resemble mined emeralds.

This was the method Carroll Chatham pioneered when he grew the first commercially viable lab emeralds in the 1930s.

Carroll Chatham: The Man Who Grew Emeralds

In 1935, a young San Francisco scientist named Carroll Chatham succeeded in growing gem-quality emerald crystals in his laboratory using the flux method.

It was a breakthrough that had challenged chemists for over a century.

Before Chatham’s work, producing large, jewelry-quality emerald crystals in a laboratory had remained a significant scientific challenge.

The French chemist Jacques Joseph Ebelman had proposed the flux concept as early as 1848, but nobody had produced stones large enough or clean enough for jewelry.

Chatham's achievement was so unexpected that when he submitted his crystals to the Gemological Institute of America for testing, they initially certified them as natural Colombian emeralds.

Further examination confirmed that the stones were laboratory-grown emeralds because their quality and appearance were remarkably close to natural gemstones.

Chatham went on to found Chatham Created Gems, which remains one of the most recognized names in lab-grown gemstones.

Interestingly, early lab-grown emerald production was not cheaper than mining. It took decades of technological improvements before lab-grown emeralds became a more accessible option for jewelry buyers.

A Note on Terminology: What "Lab-Grown" Actually Means

The terms "lab-grown," "laboratory-created," and "synthetic" all legally refer to gemstones with essentially the same optical, physical, and chemical properties as their natural counterparts.

These terms describe how the gemstone was created, not whether it is a real gemstone.

The FTC's 2018 Jewelry Guides confirm this.

TrueSanity uses "lab-grown" because it provides clearer information for customers comparing lab-grown emeralds with natural emeralds.

What We Sell:

Lab-grown emeralds that are real beryl gemstones (Be₃Al₂Si₆O₁₈) colored by chromium. They have the same chemistry, hardness (7.5 to 8 Mohs), and crystal structure as mined emeralds.

Grown via hydrothermal or flux methods.

What We Do Not Sell:

Green cubic zirconia, green glass, nano emerald, or any other emerald simulant.

These materials may resemble emerald visually, but they have different chemistry, hardness, and optical properties. They are not genuine emerald gemstones.

For customers searching for a real lab-grown emerald, understanding the difference between an emerald and a simulant is one of the most important steps before purchasing.

Lab-Grown Emerald Buying Guide

What Matters

Color:

Color is the most important factor when choosing a lab-grown emerald.

The best lab-grown emeralds achieve a vivid, saturated green comparable to fine Colombian stones.

Look for strong green tones with slight blue secondary hues. Avoid stones that appear too yellow-green or overly dark, as these characteristics can affect the overall appearance of the gemstone.

Clarity:

Clarity is one of the biggest advantages of lab-grown emeralds.

Unlike many natural emeralds, which commonly contain visible inclusions, lab-grown emeralds often offer cleaner appearances with fewer internal characteristics.

Look for eye-clean stones.

A high-quality lab-grown emerald gemstone should have good transparency and allow the color to remain the focus.

Cut:

A well-cut lab-grown emerald helps maximize color saturation and minimize windowing, which is the see-through effect that can make a gemstone appear less vibrant.

The classic emerald cut, a step cut with a rectangular shape and clipped corners, was originally developed to showcase this gemstone’s unique color and structure.

Growth Method:

The growth method can influence the appearance of a lab-grown emerald.

Hydrothermal growth tends to produce cleaner stones with vivid color.

Flux growth often creates a more natural-looking appearance with characteristic inclusions.

Both hydrothermal and flux-grown emeralds are genuine gemstones. The right choice depends on whether you prefer higher clarity or a more natural-looking internal appearance.

What Doesn't Matter

Oil treatment status:

Lab-grown emeralds are almost never oiled because they typically do not require fracture filling.

When buying lab-grown emerald jewelry, oil treatment is generally not a concern because these gemstones are created with fewer fractures compared with many natural emeralds.

Origin Prestige.

Natural emeralds are often valued partly for geographic origin, such as Colombian, Zambian, or Brazilian emeralds.

Because lab-grown emeralds are created in controlled environments, they do not have the same geographic origin factor. Their value comes from gemstone quality, craftsmanship, and overall design rather than where they formed.

Resale Value:

Like many lab-grown gemstones, lab-grown emeralds are a purchase rather than an investment.

They are chosen for their beauty, accessibility, and personal meaning rather than future appreciation.

They deliver the same green color that has fascinated people for centuries at a more accessible price point.