Cut
Firstly, you’ll want to consider the cut grade of your stone. The quality of the cut is widely considered the most important factor as it affects the beauty and sparkle of your diamond the most. The angles and proportions of the facets (small flat planes) affect the fire, brilliance and scintillation of your stone.
Fire is the scattering and splitting of light into rainbows.
Brilliance is the white light reflected back to your eye
Scintillation is the patterns and flashes of light and dark as the diamond moves.
A poor cut can make your diamond look dark, dull and small, and allow light to leak out instead of reflecting back to your eye.
Color
With diamond color, what is actually being graded is the absence of color. Color in a diamond appears like a warm tint that can be yellow, brown or gray in tone. The less tint a diamond has the higher the color grade. Diamonds are rated on a scale from D to Z (D being the top of the scale). A lower color grade generally means a lower price, but the difference between adjacent colors is extremely subtle. When considering a diamond, it is important to choose one that looks the most beautiful to you and fits within your budget. Each diamond is just as unique as each person, so at the end of the day, the most important factor is how happy you are with your choice.
Carat
Carat is often thought of as a measure of how big a diamond is, but it actually refers to the weight of a diamond. The term “carat” refers to the carob seed which ancient gem traders would use to measure the weight of their gemstones. Carob seeds are uniform in their weight, so it insured accuracy when trading. The higher the weight of a diamond the more rare it is! Not every diamond that weighs the same will look the same or have the same value. There is some correlation between how big a diamond looks and its weight. However, a poorly cut diamond can have a much smaller diameter compared to one with an ideal cut.
Clarity
Diamonds are formed under immense heat andpressure deep in the earth - so it's normal for them to have tiny internal
characteristics called inclusions. Each diamond’s clarity grade is dependent on the number, size, color and position of their characteristics and the scale tells you how visible they are. The scale starts at the top with flawless (FL) and then continues down with internally flawless (IF), Very Very Slightly Included (VVS), Very Slightly Included (VS), Slightly Included (SI) and Included (I). Each category is then subdivided for more accuracy. Many inclusions are too tiny to be seen without magnification. To the naked eye, a VS1 and SI2 diamond may look exactly the same, but there is a quality difference between them so much like the color scale, a higher clarity will mean a higher price. No two diamonds have the same clarity characteristics, so we often think of them as fingerprints or birthmarks. Which tells you that your diamond is your diamond.
