A 3-carat diamond refers to a diamond that weighs three carats, which is equivalent to 600 milligrams. The carat weight is a key factor in determining a diamond's value, with larger diamonds generally being more expensive. The size of a 3-carat diamond can vary based on its cut, as different cuts can affect how the diamond appears visually. In addition to carat weight, the quality of a diamond is assessed using the Four Cs: cut, color, clarity, and carat. A well-cut 3-carat diamond can appear larger and more brilliant than a poorly cut diamond of the same weight. Buyers often consider these factors to ensure they choose a diamond that meets their preferences and budget.