First and foremost, it is important to know that Lab-Grown Diamonds are NOT imitation stones (such as cubic zirconia, zircon, Swarovski, glass, spinel, Diamonique, etc.) NOR diamond simulants (such as moissanite, etc.).
In simple words, Lab-Grown Diamonds are as-close-as-you-can-get-to-diamonds, however much cheaper in price because instead of being formed naturally in Earth's mantle (and then delivered to the surface by deep-source volcanic eruptions), they are developed in laboratory (man-made) under similar environmental conditions as natural diamonds. For this reason, Lab-Grown diamonds are considered to be the only non-simulant and conflict-free alternative to natural diamonds because they possess the identical chemical, physical, and optical properties as natural diamonds originating from nature.
Both Lab-Grown and naturally mined diamonds have the same chemical composition and atomic structure, producing the very same durability, fire, and sparkle. Laboratory-grown diamonds are truly a testament to the use of technology and human achievement.
Getting more into the science, "Lab-Grown" most accurately describes the man-made production process in which the crystal structure is grown from the "seed diamond". Lab-Grown diamonds are the result of an extemporaneous crystallization process rather than a synthesis of compounds. Lab-Grown diamonds utilize a Chemical Vapor Deposition (CVD) process or a High-Pressure High Temperature (HPHT) method that causes carbon atoms to crystallize into the structure that renders them harder than any other form of carbon and harder than any other material.
Both processes require advanced technological equipment and both produce rough diamonds that are then cleaned, cut, and polished in the very same way that naturally occurring, mined diamond rough is processed. Diamond growth can be initiated only when a pre-existing diamond seed or a sliver of the diamond substrate is present for the carbon atoms to attach to and “learn” the diamond’s strong tetrahedral crystal lattice. The “seed” essentially serves as a blueprint for the crystallization process as carbon atoms stack one-by-one on the carefully selected seed.
Lab-Grown Diamonds are graded to the same carat, clarity, color, and cut specifications as mined diamonds and they can be accompanied by the same type of Diamond Grading Reports written by leading independent gemological institutes and certified appraisers.
Classifying Diamonds by their "Type":
"Type I" diamonds account for approximately 98% of all-natural diamonds and contain Nitrogen impurities. Type II diamonds, on the other hand, contain no measurable Nitrogen impurities. All colorless lab-grown diamonds (regardless of how they’re created), lack Nitrogen and are classified as "Type IIa". Note that "Type IIb" diamonds share the same lack-of-Nitrogen as "Type IIa", but also contain Boron impurities. Thus, screening for Nitrogen (actually lack-of-Nitrogen) is one way that testing devices use to quickly identify diamonds that could be man-made.
A brief science history: In early-1900's scientists noticed that certain kinds of diamonds displayed similar features, so they grouped them into two main categories: "Type I", and "Type II" (based on differences in transparency under UV radiation). Thereafter, they were able to further divide "Type I" and "Type II" diamonds into two sub-categories by the arrangement of Carbon and impurity of atoms in the diamond structure. In the mid-1900s scientists discovered that Nitrogen was the principal chemical impurity in diamonds and that while "Type I" diamonds contained this impurity, "Type II" diamonds did not. The below diagram shows a simplified version of the diamond type classification system. Type I (top row) and type II (bottom row) diamonds can each be divided into two subcategories based on the arrangement of Carbon and impurity of atoms in the diamond structure.
As shown above, the vast majority of natural diamonds are "Type Ia", containing plentiful Nitrogen in clusters or pairs. It is important to understand that this kind of diamond cannot be grown artificially. "Type Ib" diamonds contain scattered and isolated Nitrogen atoms that are NOT in pairs or clusters, and they are rare in nature. "Type IIa" diamonds contain almost no Nitrogen, while "Type IIb" diamonds contain the element Boron. Lab-grown diamonds mainly correspond to "Type IIb" diamonds. Note that types Ib, IIa, and IIb are all rare categories among natural diamonds.
Myths & Truths:
- Myths #1: Lab-grown diamonds aren't real diamonds.
Lab-Grown Diamonds are chemically, physically, and optically the same as natural diamonds. The difference is in the growth process and origin; that is, a lab-grown diamond is created in a controlled environment under similar conditions as its natural counterpart. Therefore, it is important to understand that Lab-grown diamonds are NOT what is referred to as diamond-simulants (e.g. Moissanite, White Sapphire, etc.). However, the Federal Trade Commission disallows the term "real" to describe a lab-grown diamond.
- Myth #2: An experienced gemologist can identify a lab-grown diamond with a standard 10x magnification jeweler's loupe.
While there are several origin indicators associated with lab-grown diamonds, not all indicators appear in every lab-grown diamond (some may even contain no indicators). Conclusive identification of lab-grown diamonds requires specialized laboratory instruments; and in difficult cases, advanced knowledge.
- Myth #3: Lab-grown diamonds are not as hard as natural diamonds.
Once again, remember that lab-grown diamonds are 100% chemically, physically, and optically identical to diamonds. This also applies to hardness. Both lab-grown diamonds and natural diamonds rest comfortably at the top of the Mohs hardness scale of 10.
- Myth #4: CVD (Chemical Vapor Deposition) lab-grown diamonds are better than HPHT (High-Pressure High Temperature) lab-grown diamonds.
CVD and HPHT are two methods to grow lab-grown diamonds. The growth process is unique, but neither is superior.
- Myth #5: All lab-grown diamonds read as diamonds on Moissanite/Diamond probe-type testers.
Diamond probe testers use thermal conductivity (i.e. the ability of a material to transfer heat). Since lab-grown diamonds possess the same properties as diamonds, lab-grown diamonds will always read as diamonds on a thermal probe. By contrast, Moissanite probe testers measure electrical conductivity (i.e. the ability of a material to transfer electricity). Thus, the vast majority of lab-grown diamonds will not test as Moissanite because they lack electrical conductivity. There's one small exception here: "Type IIb" lab-grown diamonds, because "Type IIb" lab-grown diamonds contain Boron impurities. These typically blue (though not always; some may be colorless) lab-grown diamonds are electrically conductive and will test as Moissanite.
- Myth #6: All lab-grown diamonds 1.25 carats and larger are only created using the CVD (Chemical Vapor Deposition) method.
Actually, the HPHT (High-Pressure High Temperature) process can grow larger diamonds than the CVD method. This is due to the specifics of the growing equipment utilized in both processes. The largest CVD diamond on record (as of this writing) is 9.04 carats. The largest HPHT diamond on record? An impressive 15.32 carats (as of this writing).