The Science record; a compendium of scientific progress and discovery . The brilliant (Fig. 2) displays the lustre of the stone tothe greatest advantage, and is described as obtained bytwo truncated pyramids united together by one commonbase, the upper pyramid being much more truncated thanthe lower, a is the crown and e the collet, the two princi-pal divisions formed by the girdle c. d is the table, andthe opposite side below, the culasse. The faces are calledfacets, and, including table and culasse, may number sixty- Tuf. 4. THE ROUGH DIAMOND. four. The rose diamond (Fig. 3) has a crown but
The Science record; a compendium of scientific progress and discovery . The brilliant (Fig. 2) displays the lustre of the stone tothe greatest advantage, and is described as obtained bytwo truncated pyramids united together by one commonbase, the upper pyramid being much more truncated thanthe lower, a is the crown and e the collet, the two princi-pal divisions formed by the girdle c. d is the table, andthe opposite side below, the culasse. The faces are calledfacets, and, including table and culasse, may number sixty- Tuf. 4. THE ROUGH DIAMOND. four. The rose diamond (Fig. 3) has a crown but no collet,that is, one side is flat; and it is usually made from stonesand fragments which would not, without loss, form goodbrilliants. Then there are table diamonds, which are flatand have little lustre, and bastard diamonds, or those 01mixed shapes. TECHNOLOGY. 89 In the accompanying engraving (Fig. 4) is representedan enlarged section of the rough gem, showing the grain,along which it may be as cleanly cleft as a piece of resemblance to the latter substance is increased by
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Keywords: ., bookcentury1800, bookdecade1870, booksubje, booksubjecttechnology
