The 4Cs: Carat, Color, Clarity and Cut | Kay
Carat
• Diamonds are weighed in units called carats. A carat is measured in increments called points. One carat is equal to 100 points.
• Carat weight is the easiest of the 4Cs to determine because it is measured on a diamond scale.
• Two diamonds of equal carat weight can have very unequal value depending upon the cut, color and clarity of each.
Color
• Color refers to the body color of the diamond. Fancy color diamonds aside, the best, most beautiful color for a diamond is no color at all.
• The Gemological Institute of America (GIA) has created a scale to measure diamond color, ranging from D (colorless) to Z (yellow). Fancy color diamonds are graded Z and higher.
• Most KAY diamonds are graded "near colorless" - between G and J on the color scale. At a J grade and beyond, the human eye can start to detect a yellow tint.