The cut of a natural diamond determines how it interacts with light. The Cut Grading System assesses a diamond’s cosmetic appearance, including its brightness, fire, and scintillation, which make up the way a diamond reflects light, dispersing it into color, and sparkles.

To maximize its beauty, natural diamond cutting requires a mix of artistry and precision. Which is why the cut grade also judges a diamond based on the craftsmanship that went into it, meaning the diamond’s final symmetry, polish, and proportions.

The carat of a natural diamond is the measurement of the diamond’s weight. The carat derives its name from the carob seed, a small, uniform seed with a commonly equal weight. These seeds were used to balance scales in early gem trading, before the metric carat was created as the universal form of measurement.

A full carat diamond weighs 200 milligrams, and full carat and larger natural diamonds are becoming rarer by the day as supply continues to decrease and no significant deposits have been found in decades.

Natural diamonds formed deep within the Earth, and as a result, they often carry unique markings called inclusions or blemishes. These common markings are usually the result of non-carbon elements or interruptions during the extreme heat and pressure a diamond goes through while forming deep within the Earth, and can be considered small time capsules that tell the story of the natural diamond’s formation.

A diamond’s clarity refers to the absence of these inclusions or blemishes. Natural diamonds that form without any inclusions are extremely rare and deemed “flawless” on most grading scales. These rare diamonds are some of the most valuable in the world.

A natural diamond’s color grade is usually a measure of how colorless the diamond is. Most natural diamonds appear colorless to the average shopper, but actually have slight tones of yellow or brown. The closer the stone is to colorless, the rarer and generally more valuable it is. Natural diamonds are graded on a color scale ranging from D (colorless) to Z (heavily tinted brown or yellow).

Diamonds can also form naturally in almost any color imaginable because of factors apparent in the earth when they form. Most of these natural “fancy” colors are so rare that their value can be limitless, and they are graded on a scale more closely describing the visible color.