- Nailhead
Unattractive black shadow under the center of a round brilliant cut diamond that has too deep of a pavilion. The shadow is caused by the reflection of the table. Diamonds with a nailhead look dark, lacking brilliance and life.
- National Diamond Colour Master Set
Set of certified and registered diamonds, with known colours from which other master sets may be derived.
- Natural
Part of the original “skin” of a rough diamond that has been left on the polished diamond. Naturals affect the polish grade of a diamond, but do not have a significant impact if confined to the girdle area where they are usually located.
- Natural Diamond
Diamond mined from the earth, unlike a synthetic diamond, formed completely by nature without any human intervention or treatments.
- Needle
- Nick
Type of diamond blemish that that appears as a tiny break out of the edge of a diamond, not large enough to be a called a chip and usually confined to the girdle. Nicks affect the polish grade of a diamond.