The term “white diamond” is confusing because it refers to two distinct types of stones. Most frequently, it describes a completely colorless or nearly colorless stone, which is the industry standard for traditional diamonds. However, a small, rare category is officially graded as “Fancy White,” possessing a milky, opaque appearance. Determining if a diamond is “real” requires examining its fundamental chemical composition and origin, not just its visual color.
Understanding Color Grading: Colorless vs. White
The standard for what most consumers call a “white diamond” is actually the absence of color. The Gemological Institute of America (GIA) uses a color grading scale that runs from D to Z, where D is the highest and represents a perfectly colorless stone. Diamonds in the D-F range are classified as “colorless,” while those in the G-J range are categorized as “near-colorless”.
These D-J diamonds appear transparent and bright, and they are the stones generally meant when someone asks for a “white diamond”. As the color grade moves down the scale toward Z, the stone exhibits a progressively more noticeable yellow or brown tint. The subtle differences between these grades can be invisible to the untrained eye, but they significantly affect the stone’s rarity and value.
A separate and much rarer category is the “Fancy White” diamond, graded like other colored diamonds (e.g., pink or blue). These stones are opaque and milky, unlike transparent colorless diamonds. Their white color is caused by a high concentration of submicroscopic inclusions that scatter light, creating a distinct, snow-white appearance. Fancy White diamonds are classified based on visible color saturation, contrasting with colorless diamonds valued for their lack of color.
Defining the True Nature of a Diamond
To be considered a true diamond, a stone must adhere to a specific scientific definition based on its atomic structure and chemical makeup. A diamond is a solid form of the element carbon, where the atoms are arranged in a specific crystalline structure called a diamond cubic lattice. This unique arrangement involves each carbon atom being covalently bonded to four others in a rigid, three-dimensional tetrahedral network.
This strong, uniform structure gives a diamond its unparalleled hardness, ranking 10 on the Mohs scale. Natural diamonds are formed deep within the Earth, approximately 150 miles below the surface, under immense heat and pressure. Physical properties, such as a high refractive index and thermal conductivity, stem directly from this stable, pure carbon structure.
Authenticity Beyond Origin: Synthetics and Substitutes
The concept of a “real” diamond becomes complex when considering stones that look identical but have different origins. Lab-grown diamonds, also known as synthetic diamonds, are chemically and physically identical to natural diamonds because they share the same pure carbon crystalline structure. They are grown in controlled environments using advanced methods like High-Pressure/High-Temperature (HPHT) or Chemical Vapor Deposition (CVD), replicating the natural formation process.
These lab-grown diamonds are considered real diamonds, but their origin must be disclosed to consumers. The HPHT method uses extreme heat and pressure to dissolve carbon onto a diamond seed, while the CVD method uses a vacuum chamber filled with carbon-rich gases that deposit carbon atoms layer by layer. Simulants, or substitutes, are entirely different materials that merely imitate a diamond’s appearance.
Common simulants include cubic zirconia (made of zirconium dioxide) and moissanite (made of silicon carbide), which lack the pure carbon composition of a real diamond. While a simulant may sparkle convincingly, its physical and chemical properties, such as hardness and light dispersion, are fundamentally different. For instance, moissanite is double-refractive, causing a noticeable difference in light return compared to the single-refractive properties of a real diamond.
Verification and Certification
Professional, third-party certification is the most reliable step for consumers seeking definitive proof of a diamond’s identity and characteristics. A grading report from a reputable gemological laboratory, such as the Gemological Institute of America (GIA) or the American Gem Society (AGS), provides an objective assessment of quality and verifies the stone’s origin. This report details the 4Cs (cut, color, clarity, and carat weight) and confirms whether the diamond is natural or lab-grown.
Jewelers often use quick testing devices, such as diamond testers, to differentiate a diamond from a simulant. These handheld tools primarily measure thermal conductivity, a property where diamond excels due to its lattice structure. However, since lab-grown diamonds share the same high thermal conductivity as natural diamonds, these testers cannot distinguish between them. More advanced devices are required to detect the subtle differences in growth patterns and inclusions that separate natural from lab-grown stones.