What are clarity characteristics confined to the surface of a polished diamond called?

Clarity characteristics that are confined to the surface of a polished diamond are referred to as blemishes. These surface imperfections can include scratches, nicks, or any other minor abrasions that affect the outward appearance of the diamond but do not penetrate into the stone. Understanding blemishes is crucial because they can influence a diamond's overall clarity grade, which is an important factor in determining its value and aesthetic appeal.

In contrast, inclusions are internal characteristics found within the diamond that can affect its appearance and clarity; these represent different types of clarity characteristics than surface blemishes. Flaws is a more generic term that could refer to any imperfection, whether internal or external, so it lacks the specificity of referring solely to surface characteristics. Lastly, cracks may imply a structural concern and typically denote a more serious issue than just a surface blemish. Thus, while all these terms relate to the clarity of diamonds, blemishes specifically denote surface characteristics.