coin de culasse

OBS: Coin : Nom donné aux quatre facettes résultant de la taille en croix de la couronne ou de la culasse.

OBS: Corners: The first 4 facets on the pavilion and the crown of a polished diamond; these facets are indexed at 90° to one another and form part of the main facets.
OBS: Crossworkers: establish the mains, crown and pavilion facets to specific angles and indices in two steps: 1. blocking the diamond by: establishing the initial 17 main facets, including the: - table; - 8 pavilion mains, to specific angles and indices: 4 corners; 4 pavilions; - 8 crown mains, to specific angles and indices: 4 corners; 4 bezels. 2. lapping the diamond ...