Yes, lab-grown emeralds not only exist but are an established part of the modern gemstone market, offering a chemically identical alternative to their mined counterparts. These stones are scientifically referred to as synthetic or created emeralds, as they share the exact physical and chemical properties of natural emeralds. They are grown in a controlled laboratory environment that mimics the high-pressure and high-temperature conditions deep within the Earth’s crust where the natural formation occurs. The resulting gem is a genuine emerald, differing from a mined stone only in its origin and the timeline of its creation.
Understanding Created Emeralds
Created emeralds possess the precise chemical composition of beryllium aluminum silicate ($\text{Be}_3\text{Al}_2(\text{SiO}_3)_6$) and the same hexagonal crystal structure as natural emeralds. This identical makeup distinguishes a created emerald from a simulant, such as green glass or cubic zirconia, which only look similar but are chemically different. The vibrant green color is achieved by incorporating chromium or vanadium, the same coloring elements found in natural emeralds, into the growth process.
The industry uses terms like “lab-grown,” “created,” and “synthetic” interchangeably to describe these stones, all meaning the material was produced in a laboratory setting. Because they share the same material and optical properties as their natural counterparts, they are not considered fake. Their hardness on the Mohs scale, typically between 7.5 and 8, is also consistent with mined emeralds.
Methods of Synthesis
Scientists primarily use two methods to synthesize emeralds: the Hydrothermal Process and the Flux Growth Process.
Hydrothermal Process
The Hydrothermal method replicates the specific high-temperature and high-pressure aqueous conditions found in the Earth’s natural environment. In this process, a seed crystal of colorless beryl is placed in a high-pressure vessel, called an autoclave, along with a nutrient solution containing necessary elements like beryllium, aluminum, silica, and a coloring agent. The chamber is heated to $600$ to $800$ degrees Celsius and subjected to intense pressure. This causes the nutrients to dissolve and slowly crystallize onto the seed plate over weeks to months. This method is favored for producing high-quality emeralds with excellent clarity and vibrant color saturation.
Flux Growth Process
The Flux Growth Process involves dissolving the raw materials in a molten flux solution, which acts as a chemical solvent, at refractory temperatures. As the molten solution cools very slowly over several months, the emerald crystals gradually form and precipitate out of the flux. Flux-grown emeralds often closely mimic the appearance of natural emeralds due to the slower growth rate and the ability to spontaneously nucleate, meaning the crystal starts to grow without a seed plate. Both methods require precise control over temperature and chemical composition to ensure the resulting crystals are chemically and physically identical to mined emeralds.
Key Differences and Market Value
The most reliable way for gemologists to distinguish between a created and a natural emerald is by examining the unique internal growth patterns and inclusions under magnification. Natural emeralds typically contain complex inclusions like three-phase inclusions (a tiny crystal, liquid, and gas bubble) or mineral inclusions, which serve as a natural fingerprint of their geological formation. Lab-grown stones, created in a controlled environment, exhibit different features resulting from the synthesis process.
Hydrothermal emeralds may show inclusions like chevron patterns or internal fluid trails that indicate directional growth away from the seed plate. Flux-grown emeralds often contain characteristic inclusions such as “nailhead” inclusions or remnants of the flux material itself. High-quality lab-grown emeralds often have fewer overall inclusions and better clarity than most natural emeralds.
The controlled origin and lack of rarity mean that created emeralds are significantly more affordable than comparable natural emeralds. A natural emerald of similar quality can cost three to ten times more than its lab-grown equivalent. This lower cost allows consumers to acquire a larger or clearer stone within a limited budget. Natural emeralds, however, often maintain better long-term value and are preferred by collectors due to their inherent scarcity and rich history.