Diamond Quality Factors

Please take a moment to browse the information below and / or do further research on how to purchase the right diamond for your needs. Buying diamonds can be difficult if you don’t understand the basics of Diamond Quality Factors.

Diamond Colour - Diamond Quality


Most diamonds are evaluated for colorlessness using the absence of color as the standard. A chemically pure, structurally perfect diamond has no hue, like a drop of pure water, and consequently, a higher value.

GIA’s D-to-Z color-grading system evaluates a gemstone’s degree of colorlessness by comparing it to masterstones with established color values.

GIA’s D-to-Z color-grading scale is the most widely accepted grading system in the industry. The scale of color begins with the letter D, representing the absence of color, and continues with increasing presence of color, to the letter Z.

Many color distinctions are so subtle that an untrained eye cannot see them; however, professionals can discern these distinctions and use them to evaluate a diamond’s quality.

Diamond Clarity - Diamond Quality Factors


Natural diamonds form under tremendous heat and pressure deep within the earth. They can contain a variety of internal characteristics called inclusions, as well as external characteristics called blemishes.

When evaluating diamond clarity, you should consider the number, size, relief, nature and position of inclusions in a diamond’s surface. No diamond is perfectly pure; the closer it comes to perfection, the higher its value.

The Gemological Institute of America (GIA) Clarity Scale has 6 categories, some of which are divided into additional subcategories.

Only experts can spot the inclusions and blemishes that make a diamond less than perfect. To the naked eye, a VS1 and an SI2 diamond may appear identical, but the fact remains that these diamonds differ greatly in terms of quality. This is why experts assess clarity with care.

Diamond Cut - Diamond Quality Guide


In a diamond, the cut determines how light enters the stone and reflects from its facets. Cut is often referred to as shape (round, emerald, pear), but cut grade is really about how well a diamond’s facets interact with light.

Only precise artistry and workmanship can fashion a stone into a diamond, which reflects a range of light known as brilliance. The quality of a diamond’s cut is crucial to the diamond’s final beauty and value. It is the most complex of all the 4Cs to analyze.

The Gemological Institute of America’s (GIA) Cut Grading System evaluates seven factors in a round brilliant diamond: brightness, fire, scintillation; weight ratio; durability; polish; and symmetry.


A diamond reflects both internal and external white light.


The dispersion of white light into a spectrum of colors.


The sparkle of a diamond comes from the way light is reflected through its structure.
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Carat Weight - Diamond Quality Information

Carat Weight

A diamond’s carat weight (also known as its weight or mass) is a measurement of how much it weighs. A metric carat is 200 milligrams.

One carat is divided into 100 ‘points,’ so measurements can be made to the hundredth decimal place. A jeweller might describe the weight of a diamond of less than one carat using its ‘points’ alone.

For example, a jeweler might refer to a 0.25 carat diamond as a ‘twenty-five pointer.’ Larger diamonds are measured in carats and decimals. A 1.08-carat stone is described as ‘one point oh eight carats.’

The price of a diamond increases with the carat weight of the stone, because larger diamonds are rarer and more desirable. However, two diamonds of equal carat weight can have very different values (and prices) depending on three other factors within the 4Cs: Clarity, Color, and Cut.

A diamond’s value is determined using the 4Cs (cut, color, clarity and carat weight), not just carat weight.

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