Blemishes Pertaining to Diamonds
This refers to any imperfection that is found on or in a diamond.
Blemishes Due to Crystal Structure
Natural (N) Part of the original crystal structure remains on the diamond.
Surface Graining (SGr) Translucent lines that appear on the surface of a finished diamond.
Blemishes Caused by Deterioration (Wear)
Scratch (S) A dull, thin white-colored line across the surface of the diamond.
Nick (Nk) Tiny notch close to the facet junction or girdle.
Abrasion (Abr) Small nicks that are found along the facet junctions. These produce fuzzy and or white lines, which result in edges that are not sharp and crisp.
Blemishes Due to Cutting Process
Extra Facet (EF) Additional facet located on the girdle that is not part of the desired cut.
Burn Marks (Brn) Uneven polishing caused by structure irregularity can cause the surface of the diamond to turn hazy from wear.
Pit (Pit) A small opening, which looks like a white dot.
Rough Girdle (RG) Pitted or irregular girdle.
Polish Lines (PL) Colorless, and often hard to see find parallel lines, ridges, or grooves, which are left by the process of polishing a diamond.
Blemishes Pertaining to Pearls
Spots, wrinkles, blisters, or small pits that appear on a pearl’s surface.