How to Select the Perfect Diamond at Blue Nile

A diamond acts as a prism dividing the light into a spectrum of colors reflecting light as colorful flashes called fire. Less color in the diamond means more color in the fire and a higher color grade. Absolutely colorless is ideal but extremely rare.
Diamonds that are absolutely clear are the most sought after and bring the most money. Detracting from the pure beauty of the diamond are inclusions - scratches or trace minerals. The GIA and AGSL use a rather complicated method of determining clarity according to number, location, type, and size of the inclusions present in a diamond. A flawless diamond has no internal or external flaws and is very beautiful and rare. After you have selected the cut (we’ll get there in a minute), color, and clarity of a diamond, determining the carat weight is a cinch. Large diamonds cost more (and the price goes up exponentially) because they’re less likely to be found than smaller diamonds. A two-carat diamond will bring more than two one-carat diamonds of the same quality. 

So, we now know something about color, clarity, and carat weight, but we haven’t discussed what it is that makes a diamond brilliant. Cut determines brilliance. According to Blue Nile, “The diamond’s proportions, specifically the depth compared to the diameter of the diamond, determine how well light will reflect or refract within the diamond.” When it comes to brilliance, the cut of the diamond will determine how well light travels through it causing it to either appear shallow, just right, or too deep. If the brilliance is shallow, light is lost out the bottom, and if it’s too deep, light escapes out the sides causing the diamond to look dark and dull.