The debate surrounding lab-grown diamonds often stems from confusion over the term “synthetic.” While scientifically “synthetic” means human-made, consumers often interpret it as “fake” or an “imitation” stone. A lab-grown diamond (LGD) is created in a controlled environment, not mined from the earth. The fundamental truth is that an LGD is composed of the exact same material as a mined diamond, making it a real diamond; its origin is the only difference.
The Identical Atomic Structure
A diamond is defined by its chemical composition and its internal crystalline structure, regardless of where it formed. Both lab-grown and mined diamonds consist of pure carbon atoms arranged in a characteristic isometric crystal lattice. This highly dense, three-dimensional structure gives a diamond its unique material properties.
Because they share this identical atomic arrangement, lab-grown diamonds exhibit the same physical, chemical, and optical characteristics as their mined counterparts. They possess the highest possible score of 10 on the Mohs hardness scale, making them the hardest known material. They also share the same high refractive index, which determines the stone’s brilliance. Scientifically, advanced gemological instruments are required to distinguish between a lab-grown and a mined diamond, often relying on subtle differences in growth patterns or trace elements.
How Lab Grown Diamonds Are Created
The creation of diamonds in a laboratory relies on replicating the intense conditions under which diamonds naturally form deep within the Earth’s mantle. There are two primary industrial methods used to grow gem-quality diamonds: High-Pressure/High-Temperature (HPHT) and Chemical Vapor Deposition (CVD). Each process starts with a small diamond “seed” crystal to guide the growth of the new stone.
High-Pressure/High-Temperature (HPHT)
The HPHT method is the older technique, designed to directly mimic the geological conditions of a diamond’s formation. This process places the diamond seed in a chamber with a pure carbon source, such as graphite. It subjects the material to extreme pressures, typically around 5 to 6 Gigapascals (GPa). Simultaneously, temperatures are raised to approximately 1,300 to 1,600 degrees Celsius, often with the help of a metal catalyst. Under these conditions, the carbon dissolves and crystallizes onto the seed, growing a full diamond in a matter of days to a few weeks.
Chemical Vapor Deposition (CVD)
The CVD method is a newer technique that uses a vacuum chamber and a carbon-rich gas, most commonly methane. The chamber is heated to a lower temperature range, usually between 700 and 1,200 degrees Celsius. A microwave beam is used to break down the gas molecules into a plasma cloud. The individual carbon atoms then deposit layer by layer onto the diamond seed. This method typically takes several weeks. The resulting diamonds are often subjected to a post-growth HPHT treatment to improve their color and clarity, as they sometimes develop a brownish tint during the initial growth phase.
Navigating Industry Terminology
The term “synthetic” became a source of consumer confusion due to its double meaning, leading regulatory bodies to clarify the language used for lab-grown products. The U.S. Federal Trade Commission (FTC), which governs commercial transparency, updated its guidelines to remove the word “natural” from the definition of a diamond. This change acknowledges that a diamond is defined by its chemical structure, not its origin.
The FTC discourages the use of “synthetic” in isolation for lab-grown diamonds because the term can misleadingly suggest the product is not a real diamond. Instead, the commission requires clear and conspicuous disclosure of the stone’s origin. Modifiers such as “laboratory-grown,” “laboratory-created,” or “man-made” must be used whenever the term “diamond” is used. These regulated terms accurately convey that the stone was grown in a lab while affirming its identity as a diamond.
A lab-grown diamond must also be strictly differentiated from a diamond simulant. Simulants, like Cubic Zirconia or Moissanite, are materials that look similar to a diamond but possess a completely different chemical composition and atomic structure. While a lab-grown diamond is chemically pure carbon, a simulant is an imitation made of non-diamond material. Precise labeling ensures consumers understand they are purchasing a genuine diamond that was grown above ground.