What types of inclusions are most frequently found in diamonds?

The inclusion types most frequently found in diamonds include pinpoints, feathers, and knots. Pinpoints are small, typically microscopic inclusions that can appear as tiny dots within the diamond. They are often formed by trapped gas or mineral remnants from the diamond's formation process. Feathers are internal fractures that may resemble a feather's structure and can be critical for determining a diamond's durability. Knots are more significant inclusions that can appear as small, irregular masses within the diamond, often consisting of multiple crystal structures embedded in the host diamond.

These specific inclusions are common due to the natural formation process of diamonds deep within the Earth's mantle, where various environmental conditions can lead to the development of these characteristics. Understanding these inclusions is crucial for grading diamonds, as they significantly affect clarity and overall value. In contrast, large flaws, grains and dust, and air bubbles are less commonly referenced in discussions about diamond inclusions.