Polish Marks (6.40)
Polish marks are also caused by problems in dealing with the grain of a diamond during the cutting process. If the cutter is too far off from a perpendicular position in his approach to the single grain that he is attacking, an irregular surface texture occurs. Sometimes this can be so severe that the surface is very similar in appearance to a burn. The surface becomes frosted, with a bubbling-like effect taking place. Some dealers call this “lizard skin”.
Waves and/or grooves can appear which are very easy to spot by using the reflection of light across the surface of the facet in question. Sometimes the raised areas are partially surrounded by trailing lines or tails. Surface graining and internal graining can be mistaken for polishing marks or lines and vice versa. By checking their consistency and depth, the difference is easily established.