Off-center Culet - A culet that, due to differences in the angles of the opposite pavilion facets, is off center with respect to the girdle outline.
Off-center culet - A major problem in gemstone cutting. An off-center culet seriously effects the symmetry of a stone.
However, stones that appear lopsided below the girdle or that have off-center culets are more tolerated in sapphire than in most other gem species.
Diamonds with a symmetry rating of "Poor" or "Fair" often times suffer from external imbalances such as an off-center or tilted table, off-center culet, misshapen facets, or wavy girdle. Diamonds with ratings of "Good" or better are most preferred.
Asymmetrical girdle outline
Off-center culet or keel line
Off-center table facet
Overly narrow/wide shoulders
(pears and heart shapes) ...
Symmetry is a grading term for the exactness of shape and placement of facets. Variations in symmetry include off-center culets and tables, poor facet alignment, misshapen facets, out-of-round girdles, and wavy girdles.
Reflection ...
Many asymmetrical round stones are not completely round, or have misshapen facets or off-center culets.
stone - how identical and exact the size as well as placement of each facet is. Symmetrical imperfections include off-center table, wavy girdle, misshapen or extra facets, asymmetrical girdle outline, crown and pavilion mismatch, off-center culet ...
 See also: Pavilion, Symmetry, Jewel, Girdle, Culet
  
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