- Natural - Also known as Indented Natural.
A natural is an inclusion that extends into the diamond from the surface. The natural can be a portion of the original surface (or skin) of the diamond (rough) or an opening left when a surface-reaching crystal is worked during polishing.
- Needle - A thin, elongated crystal inclusion, which literally looks like a needle.
- Nick - A small notch on a facet junction (usually on the girdle or culet).