A cavity is an angular opening in the surface of a diamond. It forms when part of a feather breaks away, or when a surface-reaching crystal comes out during polishing.
In more detail
A cavity is an opening in the surface, left by a feather or a lost crystal. GIA lists it among the inclusions.
On a grading report
Drawn in red and green together on the clarity plot of a full GIA report. A Dossier has no plot but can name it in its list of up to four.
Related terms
- Feather: A feather is the general trade term for a break in a gemstone. It often looks white and feathery.
- Knot: A knot is a white or transparent diamond crystal that reaches the surface after the stone is cut.
- Chip: A chip is a shallow opening in the surface, caused by damage. It is usually at the girdle edge, a facet junction or the culet.
- Inclusion: An inclusion is a clarity characteristic inside a diamond, or one that reaches the surface from inside.