The clarity is given by the number of foreign substances included in the diamond. Such in-homogeneities may be internal in which case they are called inclusions (black “carbon“, white “ice“, cracks, etc.). They arise during particular phases of crystal formation. Further, defects may be of an external character (scratches, extra facets), which may be caused through cutting and polishing or defects that couldn´t be removed during processing. The size and the placing of these inclusions are key factors for the process of grading clarity. A standard diamond grading loupe of 10x magnification is used for measuring clarity.
THE INTERNATIONAL SCALE OF DIAMOND CLARITY
LC – Loupe Clean or IF - Internal Flawless If the diamond is transparent without any visible inclusions, it is loupe-clean. VVS* (Very Very Small) (VVS 1, VVS 2) Very very small inclusions hardly detected by a diamond grading loupe. SI* (Small Inclusions) (SI 1, SI 2) Small inclusions easily found by a diamond grading loupe but invisible on naked eye from the table side. P I (Pique) Medium inclusions which can be easily located by a loupe but hardly seen on naked eye. P II (Pique II) A big number of large inclusions easily detected on naked eye. P III (Pique III) Big and numerous inclusions easily detected on naked eye and influencing the brightness of the diamond. *Other degrees of the grading VVS, VS and SI and their two subcategories can be used only for grading of 0.47 ct diamonds and bigger. Using terms like “pure”, “pure to eye”, “commercial pure” or other confusing expressions are not allowed.