Cut, colour, clarity, and carat. Four criteria that tell you what you're actually buying.
Every diamond is graded on four key characteristics: cut, colour, clarity, and carat weight. Together, these determine how a diamond looks, how it performs in light, and what it costs. Understanding them helps you choose well. For a deeper look, see the IGI 4Cs guide.
Cut
Cut is the single biggest factor in how a diamond looks. It determines how light moves through the stone, how much it sparkles, and how bright it appears. A well-cut diamond returns light evenly through the top; a poorly cut one lets light leak out the sides.
Colour
Colour grading measures how close a diamond is to being completely colourless. The scale runs from D (colourless) down to Z (noticeable colour). Most differences between adjacent grades are invisible to the naked eye, so this is one area where you can often save without compromising on appearance.
Clarity
Clarity refers to internal inclusions and surface blemishes. Fewer and smaller inclusions mean a higher grade. Many inclusions are microscopic and invisible without magnification, so a diamond can grade well below "flawless" and still look completely clean to the eye.
Carat weight
Carat is a unit of weight, not size. One carat equals 0.2 grams. Two diamonds of the same carat weight can look different sizes depending on how they are cut. A higher carat weight does increase the price, but it is worth considering all four Cs together rather than focusing on weight alone.