Which factors are used to identify a well-cut diamond?

A well-cut diamond is primarily identified by its proportions, symmetry, and light performance. These factors play a crucial role in how the diamond interacts with light, which directly affects its brilliance and sparkle.

Proportions refer to the measurements of the diamond, including the depth, table size, and angles of the facets. The ideal proportions can maximize light return through the diamond, enhancing its visual appeal. Symmetry involves the alignment and precision of the facets; a well-symmetrical diamond will reflect light evenly and beautifully. Light performance describes how effectively a diamond can reflect, refract, and disperse light. A diamond that excels in these areas will show greater brilliance and fire, making it more desirable.

In contrast, while carat weight and color are important qualities of a diamond, they do not specifically indicate how well the diamond is cut. The number of inclusions, which refers to internal imperfections, may affect clarity but does not directly comment on the cut quality. Similarly, the diamond's origin and certification provide context about its authenticity and grading but are not inherent to the cut itself. Consequently, proportions, symmetry, and light performance are the definitive factors for assessing a well-cut diamond.