Every rough diamond is carefully examined to determine the cut – or shape – that will bring out its maximum brilliance. A cut and polished diamond’s radiance is based on its relationship with light: how light strikes the surface, how much enters the diamond, and how much – and in what form – light returns to your eye. A diamond cut with correct proportions maximizes its interaction with light.

We often refer to the most popular types of diamonds used in jewelry as “colorless.” This term, however, isn’t exactly true because most diamonds actually have a small amount of color.

The Gemological Institute of America (GIA) has created a color scale that extends from D (colorless) to Z (light yellow or brown). Each letter represents a level of discernable color, and the higher the grade, the more valuable the gem. Color grades are determined by highly trained experts who examine each diamond in a controlled environment.

Although extreme heat and temperatures are critical in forming diamonds, they also create imperfections in the gems known as inclusions. Inclusions are like a diamond’s natural “fingerprint” (truly flawless diamonds are extremely rare) and contribute to the gemstone’s character. A diamond’s clarity is a measure of its inclusions. The GIA Clarity Scale includes 11 clarity grades ranging from Flawless to I₃.

Carat weight refers to a diamond’s weight, and according to tradition, was based on the weight of a carob seed. You can imagine that this led to quite a bit of variance, so a standard unit of measure – the metric carat – was adopted worldwide in 1905. One carat, or metric carat, equals 200 milligrams in weight. Each carat is divided into 100 points. A 1-carat diamond = 100 points, a .75-carat diamond = 75 points, etc. Remember, diamonds with the same carat weight can vary greatly in value, depending on color, clarity, and cut. Choosing the perfect diamond is a matter of deciding what matters most to you – size or quality – then finding the best combination of factors to suit your needs.