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Guide
A diamond is described by a specific set of measurements and gradings, not by adjectives. This guide covers the 4Cs, certification, fluorescence and proportions, and treats natural and laboratory grown diamonds with the same level of detail so you can compare them on the facts.
Cut, color, clarity and carat weight together describe how a diamond looks and how it is graded. No single C determines value on its own; two diamonds of the same carat weight can look and cost very differently depending on the other three.
Cut grades how well a diamond’s proportions, symmetry and polish let it return light to the eye. It is the only one of the 4Cs that depends on human workmanship rather than the stone as it was found or grown, and it has the largest effect on brilliance. A well cut diamond of slightly lower color or clarity often looks livelier than a poorly cut diamond with better paper grades.
Color grades the absence of color in a white diamond, from D (colorless) through Z (light yellow or brown). Grades are assigned by comparing a stone under controlled lighting against master stones of known grade. Differences between adjacent grades are often subtle to the eye and easier to see in a side by side comparison than in a stone worn alone.
Clarity grades internal inclusions and surface blemishes, from Flawless through Included, under ten power magnification. Most inclusions at the higher clarity grades are not visible to the naked eye; what matters for day to day wear is whether an inclusion is visible without magnification and whether it sits somewhere that affects durability, such as near an edge.
Carat is a unit of weight, one fifth of a gram, not a measure of size on its own. Two stones of the same carat weight can face up as different diameters depending on how deep or shallow they are cut, which is why cut and proportions matter alongside the raw weight.
A grading report from an independent laboratory documents a diamond’s 4Cs, proportions and any treatments, using standardized methods rather than a seller’s own opinion. The three laboratories most commonly referenced in the trade are GIA (Gemological Institute of America), IGI (International Gemological Institute) and GCAL (Gem Certification and Assurance Lab). Grading standards and strictness can vary somewhat between laboratories, which is one reason the issuing lab is worth noting alongside the grade itself, not just the grade in isolation.
Where a diamond in our catalog carries a report, the issuing laboratory and report number are listed on the product page.
Fluorescence describes how a diamond reacts to ultraviolet light, graded from None through Very Strong. In most diamonds, faint to medium fluorescence has little visible effect in normal lighting. In rare cases, strong fluorescence can make a diamond appear slightly hazy or milky, most often in stones that are also higher on the color scale. Fluorescence is not itself a defect; it is another data point worth weighing alongside the 4Cs rather than avoiding on principle.
A grading report also lists a diamond’s proportions: table percentage, depth percentage, crown and pavilion angles, and girdle thickness. These figures describe the geometry behind the cut grade in more detail than the single letter grade does, and they are what a jeweler looks at when comparing two stones with the same overall cut grade. Girdle thickness in particular affects durability: a girdle that is too thin can chip more easily, while one that is too thick adds weight without adding visible size.
Natural and laboratory grown diamonds are both made of crystallized carbon and are graded on the same 4Cs scales by the same laboratories. They differ in how they are formed, and that difference carries through to how each is priced and how each behaves in the resale market.
Natural diamonds form deep underground over a very long geologic timescale and are brought to the surface by volcanic activity, then mined. Laboratory grown diamonds are produced in a controlled setting, using one of two processes, high pressure high temperature (HPHT) or chemical vapor deposition (CVD), which recreate the conditions needed for carbon to crystallize into diamond over a period of weeks rather than over geologic time.
Both are graded against the same 4Cs criteria described above. A laboratory grown diamond’s report states that it is laboratory grown, and reputable labs also mark the girdle of the stone itself as laboratory grown, so the distinction is documented rather than left to inference.
Laboratory grown diamond prices have fallen substantially over the past several years as production has scaled up, and a laboratory grown stone is typically priced well below a natural stone of comparable size and grade. Natural diamond pricing is tied to a smaller, slower growing supply and has followed a different trajectory. Resale value also behaves differently between the two: a laboratory grown diamond has generally retained a smaller share of its original price on resale than a comparable natural diamond. We do not represent either natural or laboratory grown diamonds as an investment; both are priced and sold as jewelry to be worn.
Natural and laboratory grown diamonds are listed together on our loose diamond pages with the same specification shown for each, so you can compare shape, carat, color, clarity, cut and certification directly. If you would rather have an adviser talk through the trade offs with you, book a consultation.