An inclusion is a clarity characteristic inside a diamond, or one that reaches the surface from inside.
In more detail
Small crystals can be trapped while a diamond grows, and the crystal itself can grow irregularly. Crystals, pinpoints, clouds, needles and feathers are inclusions.
On a grading report
Named in the key to symbols. On GIA's plot most inclusions are red. Cavities, indented naturals, knots, etch channels and laser drill holes are red and green.
Related terms
- Blemish: A blemish is a clarity characteristic confined to the surface of a diamond.
- Crystal: A crystal is a mineral crystal contained in a diamond.
- Pinpoint: A pinpoint is a very small crystal inside a diamond that looks like a tiny dot at 10x.
- Feather: A feather is the general trade term for a break in a gemstone. It often looks white and feathery.
- Cloud: A cloud is many tightly grouped pinpoints that are too small to see one by one but together look hazy.
- Clarity grade: The clarity grade says how free a diamond is of inclusions (inside) and blemishes (on the surface) at 10x magnification. GIA's scale has 11 grades in six categories, from Flawless (FL) to Included (I3).