APPENDIX 1. 

 THE CUTTING OF GEM STONES. 



The cutting of gem stones is necessary for the complete develop- 

 ment of those properties upon which their beauty largely depends. 

 Rarely does the stone, as found in nature, present those qualities 

 which make it attractive to the eye. In its natural state it is often 

 opaque, dull, or flawed, and even if transparent and flawless its form 

 is rarely adapted to the display of those characters which distinguish 

 the fashioned stone. Occasionally a stone may, without artificial 

 treatment, show to a sufficient degree those qualities which give it 

 rank; but such cases are rare, and in order that its inherent beauty 

 may be developed to the maximum it must be cut and polished. 



The several styles of cut may all be brought under one or the other 

 of the following heads: I. Those bounded by plane surfaces only. 

 II. Those bounded by curved surf aces only. III. Those bounded by 

 both curved and plane surfaces. The several examples under the 

 above heads may be tabulated thus : 

 I. Bounded by plane surfaces: 



Brilliant cut. 



Double brilliant or Lisbon cut. 



Half brilliant or single cut. 



Trap or split brilliant cut. 



Portuguese cut. 



Star cut. 



Rose cut, or briolette. 



Step brilliant or mixed cut. 



Table cut. 

 II. Bounded by curved surfaces: 



Double cabochon cut. 



Single cabochon cut. 



Hollow cabochon cut. 

 III. Bounded by curved and plane surfaces — mixed cabochon cut. 



BRILLIANT CUT. 



The brilliant cut may be described as two truncated pyramids, 

 placed base to base. The upper pyramid is called the crown, and is so 

 truncated as to give a large plane surface; the lower one, called the 

 'pavilion, terminates almost in a point. The line of union of the two 

 pyramids is called the girdle, and is the widest part of the stone. This 

 fashion of cut, though occasionally modified as to the size, mutual pro- 

 portions, and even the number of facets, requires, when perfect, 58 

 facets. The uppermost facet is called the crown, and is formed by 

 removing one-third of the thickness of the fundamental octahedron; 

 the lowermost facet is called the culet, or collet, and is formed by 



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