Diamond Polish refers to the degree of smoothness of each facet of a diamond as measured by a gemologist. When a diamond is cut and polished, microscopic surface defects may be created by the polishing wheel as it drags tiny dislodged crystals across the diamond's surface. Depending on the severity, these defects may disrupt light patterns as the light rays enter and exit the diamond. Polish grade as determined by the GIA, uses the following scale: 1. Excellent — No polish defects visible at 10x magnification 2. Very Good — Any defects are very difficult to see at 10x magnification 3. Good — Defects are difficult to see at 10x magnification 4. Fair — Defects are noticeable at 10x magnification and may be visible without magnification 5. Poor — Defects are visible without magnificationFor diamonds with a polish grade of Excellent to Good, any polishing defects are not visible to the naked eye, and should have no impact on the diamond's overall appearance. For diamonds with clarity grades of I1 or lower, even a white diamond polish grade of Fair is acceptable, since these diamonds already possess internal inclusions that are visible to the naked eye, making any diamond polishing markings less relevant. For diamonds less than .75 carats, any polish grade of Fair or better will not affect the appearance of the diamond to an untrained observer. Poor is the only polish grade that should be avoided regardless of the size or clarity of the diamond.