The observation of internal features and faults in a diamond according to commercial points of view began in the beginning of this century in Paris, which at that time was the most important trade centre for diamonds. In order to differentiate between the individual rare "clean" diamond and the large quantity of diamonds with inclusions, two designations were arrived at, "pure" for "clean" and "pique" for "spotted" diamonds.
All diamonds which showed no inclusions under a slightly magnifying loupe were also "loupe clean", the not clean stones were generally classified as "pique". Still to-day one hears sometimes: "Uris stone has a pique" which means "this stone has an inclusion".
In America towards the end of the twenties the gemological Institute of America (GIA) firstly named gradual quality designations for the classification of clarity. They expressed the increasing number and size as well as grade of recognition of inclusions. At the same time the 10 x magnification was established. In the meantime this has been accepted as an international standard for clarity grading of cut diamonds.
The first GIA designations were:
very, very slightly imperfect (WSI)
very slightly imperfect (VSJ) .
slightly imperfect (SI)
imperfect 1-3 (I 1-3)
The designation "flawless" describes according to the
American diamond nomenclature cut diamonds, free from internal and
external faults, as also external features were considered .when grading
In Europe, however, only internal faults are taken into account when grading for clarity, any external faults or features are included in the grading of the cut. The designation "loupe clean" refers therefore to cut diamonds which are free of Internal faults under a H) x magnifying loupe, but can still show external faults. The use of "loupe clean" for "flawless" is therefore not correct, as these' designations mean different things.