Knight's American mechanical dictionary : a description of tools, instruments, machines, processes and engineering, history of inventions, general technological vocabulary ; and digest of mechanical appliances in science and the arts . rgin of a stone by whichit is retained in the setting. Top ; the beveled portion between the table andthe girdle. Facet ; a small face. Culht ; a small central plane on the back. See Brilliant. Gem-cutting was not so well understood amongthe ancients as it is now, neithei are the Orientalcutters equal to those of Amsterdam. The Kuh-l-nuor was recut after coming
Knight's American mechanical dictionary : a description of tools, instruments, machines, processes and engineering, history of inventions, general technological vocabulary ; and digest of mechanical appliances in science and the arts . rgin of a stone by whichit is retained in the setting. Top ; the beveled portion between the table andthe girdle. Facet ; a small face. Culht ; a small central plane on the back. See Brilliant. Gem-cutting was not so well understood amongthe ancients as it is now, neithei are the Orientalcutters equal to those of Amsterdam. The Kuh-l-nuor was recut after coming into tlie possession ofthe queen. (See ) We read,however, of gem-cutting in Pliny and elsewhere. People bore into these red hyancinths I rubies)by means of the diamond.—Al Khazini, 12tlicentury. The principal modes of cutting may be classedunder three heads : — The Imp, brilliant, and rose cut. The trap {a b) cut consists of parallel jilanesnearly rectangularly arranged around the contourof the stone. c d repiesents a thicker stone, trapjjed in twoliights on the front and three on the back. The brilliiint cut consists of lozenge-shaped facetsalternating with triangles, and is used for the fronts tig.
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