Know Your Diamond

The Four C’s

Diamond knowledge is critical, whether you are buying or selling. Avilan™ believes that an educated consumer makes the right choices. We measure the quality of diamonds based on the following four criteria endorsed by the Gemological Institute of America (GIA), European Gemological Laboratory (EGL-USA), and all reputable gemological institutions:


The cut scale ranges from excellent to poor. A polished diamond’s beauty lies in its complex relationship with light: how light strikes the surface, how much enters the diamond, and how, and in what form, light returns to your eye. Three attributes help to form a beautifully cut diamond: brightness, fire, and scintillation.

  • Brightness is the combination of all white light reflecting from the surface and interior of the diamond.
  • Fire describes the “flares” of color emitted from a diamond.
  • Scintillation describes the flashes of light you see when the diamond, light, or the observer moves.

A polished diamond’s proportions affect its light performance. Diamonds with fine proportions, symmetry, and polish optimize their interaction with light, and have increased brightness, fire, and scintillation.

There are five levels of cut grade: Excellent, Very Good, Good, Fair, and Poor. The most common found in jewelry stores are excellent, very good and good. These three cut grades show the best and tend to look the best in jewelry.


The diamond color scale extends from D (colorless) to Z (light yellow or brown). Colorless diamonds are very rare and so nearly colorless diamonds are used in most jewelry. Color grades are determined by comparing each diamond to a master set. Each letter grade represents a range of color and is a measure of how noticeable a color is.
Some diamonds emit a visible light when exposed to ultraviolet radiation. Fluorescence is not a factor in determining color or clarity grades. In fact, it is estimated that only about 2% of diamonds are negatively affected by fluorescence.


The diamond clarity scale ranges from flawless to I3. Diamonds are formed under extreme pressure and heat; because of this it is very rare to find a diamond that has no internal or external characteristics. Such characteristics are natural and help gemologists separate natural diamonds from synthetics. They also help to identify individual stones.
The grade is based on the amount of inclusions in a stone. Inclusions refer to internal flaws such as air bubbles, cracks, and non-diamond minerals found in the diamond. Diamonds with no or few inclusions and blemishes are more highly valued than those with less clarity because they are rarer.

Carat Weight

This is the weight of a diamond measured in carats. As the carat weight of a diamond increases so does its rarity and price. One carat is divided into 100 “points” so that a diamond of 75 points weighs .75 carats. The carat-weight of a diamond is the easiest measurement to determine. Most importantly, two diamonds can be of equal carat-weight, but their value can differ greatly due to their cut, color, and clarity.

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Sparkle in the rough

Diamonds have captivated the attention of mankind for millennia and have been a symbol of everlasting love for centuries. These recognitions are likely due to the diamond’s renowned status as the hardest natural mineral on Earth, as well as to the extensive process required for diamond formation. The formation of diamond gems occurs over billions of years, when carbon materials are exposed to the high temperatures and pressures found 100 miles below the Earth’s crust. After this enduring process, diamonds must then be brought close to the Earth’s surface by deep volcanic pipes that erupt, causing magma to rush toward the surface, moving with it rocks containing diamonds. Only then can a diamond be found. After such a long process, it is no wonder these gems are highly treasured.

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Diamond Care

Coming Soon: Make sure you know how to properly care for your treasure.

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