Rather than the shape of the diamond (round, emerald, pear), the cut refers to the precise shape and positioning of a diamond’s facets and how well those facets interact with light. Cut is perhaps the most important factor in determining a diamond’s beauty, since diamonds are renowned for their ability to transmit light and sparkle intensely. It takes precise artistry and workmanship to fashion a diamond so that its proportions, symmetry, and polish deliver the sparkle we desire.
Diamond clarity refers to the flawlessness of the stone. When diamonds are born from the exposure of carbon to tremendous heat and pressure deep in the earth, the process can result in a variety of internal characteristics called "inclusions" and external characteristics called "blemishes." Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.
The ideal diamond is chemically pure and structurally perfect; making it clear to the point of colorlessness like a drop of pure water. The Gemological Institute of America (GIA) evaluates the color of gem-quality diamonds on a scale from D (colorless) to Z (saturated). GIA's D-to-Z diamond color-grading system measures the degree of colorlessness by comparing a stone under controlled lighting and precise viewing conditions to "master" stones of established color value.
The weight of a diamond is measured in “carats.” One carat equals 0.20 grams. Taken alone, carat weight does not determine a diamond’s value. Diamonds of the same carat weight can vary widely in price when clarity, color, cut and presence are taken into consideration.