Fig. 8. Grinding the table facet on a rough stone.
CHUCK DOP-STICK DOP-WAX STONE LAP
The gemstone is then removed from the dop-stick by melting the dop-wax and is dopped once more so that the plane of the polished table facet is perpendicular to the axis of the chuck and arm of the facet head ([fig. 9]). Great care should be taken by the lapidary to insure that the table of the stone is exactly perpendicular to this axis, or the proper placing of the later facets on the stone may become very difficult.
Fig. 9. Stone dopped to table facet.
TABLE FACET DOP-WAX STONE DOP-STICK
Once the stone has been properly dopped to the table facet, the lapidary is ready to proceed with the cutting of the outline of the stone. If it is to be a brilliant cut, the stone is ground perfectly round in outline; if it is to be an emerald or step cut, it is shaped so that it is square or rectangular in outline. This process is called preforming. The arm of the facet head is lowered on the post until it is horizontal, and the stone is worked against the cutting lap until the desired shape is obtained. When the preforming process is completed, the stone should have the desired outline of the finished gem ([fig. 10]).
Fig. 10. Preformed stone dopped to table facet.