1 A term applied to an included crystal of diamond that is oriented differently from the host crystal and is encountered during the fashioning process. Knots stand out as small, raised surfaces after the polishing operation.

2 Sometimes a small section of a twinned stone where the grain differs from the main mass is called a knot.

3 The term also is applied to an included diamond crystal well within the diamond that is encountered by the saw blade. Since the softest directions for sawing and polishing are used by the cutter, and included crystals have a different orientation, they present a harder direction than that being exploited.