There are various types of diamond inclusions and blemishes, with several important ones to familiarize ourselves with:
Bearding: These inclusions occur along the diamond's girdle during cutting. Improper bruting can affect the clarity grade
Graining: Resulting from crystal growth within the diamond, widespread graining can cause a hazy appearance.
Cavity: Large cavities should be avoided, as they can impact the diamond's structure, formed during polishing due to crystal movement.
Crystals: Common inclusions in diamonds, such as black crystals like carbons, are undesirable, while colorless white crystals are less problematic. Large single crystals are also less favored.
Clouds: Clouds often comprise a cluster of crystals concentrated in one area. Smaller clouds are generally not concerning, but larger ones can reduce brilliance, making the diamond appear hazy/cloudy. A GIA report stating "clarity grade is based on clouds" indicates high cloud presence.
Etch Channel: A tunnel-like hollow on the diamond's surface that extends internally, resembling a natural flaw rather than a laser-drilled treatment.
Feather: If significant, fractures within a diamond can be problematic and affect structural integrity or brilliance, especially if the diamond is colored.
Manufacturing Remnant: A minor man-made error occurs during the cutting process with modern machinery. It is a residual effect and not a clarity enhancement.
Pinpoints: Small crystals (black or white) are generally less harmful inclusions and more desirable, particularly the white ones.
Twinning Wisps: Result from growth defects or distortion during formation and can include pinpoints, crystals, feathers, etc. If small, they are harmless.
Chips: Often occur during cutting or polishing, with small chips not significantly impacting the diamond.
Indented Natural: Typically found near the girdle, this slight flaw results from polishing. It is usually benign and does not affect the diamond's brilliance.