In the trade small brilliants up to half a carat (0.47 ct) are usually only visually examined as to their brilliance effect. This is best seen by diffused light. thus eliminating strong surface luster and dispersion colors.
The proportions are roughly estimated. external and symmetry characteristics - as well as inclusions - are observed with a 10 x loupe and influence the total evaluation of cut quality.
The stones are qualitatively graded into
|Very good||Excellent brilliance, no or only very few external marks; discernable with difficulty, no or very few 'symmetry features' very thin to thin girdle.|
|Good||Good brilliance, a few externals marks, a few discernable symmetry marks, thin to medium girdle.|
|Medium||Reduced brilliance, several external marks, several and easily observed symmetry features, medium to thick girdle.|
|Poor||Obviously reduced brilliance, numerous external marks, easily visible, numerous symmetry features, thick to very thick girdle.|
|Practical Cut-Grading||Proportions - Girdle diameter|