6i 



ture of the diamond thus effected occurs in directions parallel 

 to the faces of the octahedron, which proves the octahedron to 

 be its primary form. A great many crystals admit of being 

 fractured in certain directions, which are, therefore, called planes 

 of cleavage. Advantage is taken of the brittleness of the dia- 

 mond in roughly shaping it previous to its being polished. 



The colour of the diamond is a matter of considerable impor- 

 tance as regards its value. When the diamond is colourless 

 and perfectly transparent, it is said to be of the " first water," 

 and is highly prized. But it frequently happens that the stone 

 is slightly yellow or brown, technically called " off colour," and 

 this is especially the case with Cape diamonds. An "off colour" 

 stone is, comparatively speaking, of little value, unless the tint 

 is very pure. Diamonds are sometimes found coloured green, 

 blue, rose, and even black. They then become fancy stones, 

 and their value is greatly beyond the first-water gems. The 

 lovely blue diamond formerly owned by Mr. Hope, and called 

 the Hope diamond, is quite unique. I believe it was purchased 

 for^~i8,ooo, and sold to the Duchess of Newcastle for^~25,ooo. 

 Its value may be even greater. The colour of certain diamonds 

 may occasionally be modified by heat, and a remarkable exam- 

 ple of this was observed in France some time ago. 



Months of labour, even years, with the improved machinery 

 of the present day, must be expended on a stone of large size 

 in order to convert it from the rough natural form into the 

 polished brilliant. During the whole of this time, the greatest 

 care must be bestowed on the manipulation, as a single mis- 

 take would mean the depreciation of the value of the stone to 

 the extent of hundreds or even thousands of pounds. The 

 natural shape of the diamond is but little fitted for displaying 

 the full beauties of the stone, and it generally happens that the 

 diamond in its rough form has certain imperfections which 

 greatly detract from its appearance. The object of the diamond 

 cutter is to remove those portions of the jewel in which the 

 flaws occur, to give the crystal a symmetrical and elegant shape, 

 and, by multiplying the faces of the diamond, to cause it to 

 reflect as much as possible of the light which falls on it, and 



