137 



TAB. CCCLXXIII. 



SILEX granatum. 

 Garnet. 



Div.l. Crystallized. Far. Trapezoidal. 



Garnets in trapezoidal crystals are not so common as in 

 rhomboidal dodecaedrons and its modifications, for which 

 see tabs. 43, 44, 120 and 364. They, however, occur in 

 some variety, as to the perfection with which they crystal- 

 lize; their brilliancy, and additional number of facets. 

 Like the former, they are sometimes detached from the 

 rock, or easily separated. The best seem to be most usually 

 in the least decomposed Granites. The upper figure is an 

 irregular fragment of micaceous Granite, of which the red- 

 dish part is Feldspar; the whiter part, Quartz; and the 

 whitest, Mica. The Garnets are of a good colour, and 

 have a tolerably natural polish : some are rather compressed, 

 and some have a face or four-sided truncation upon the 

 apex of the four-sided pyramid. The lower middle figure 

 is representative of those in the gangue above. The left 

 hand lower figure is a larger and nearly regular one, of a 

 dull roughish aspect, found detached, or rather having 

 fallen out of a somewhat sandy rock. The other, which is 

 larger, showing the truncation, was sent me detached, with 

 some other favours from Scotland, by the Rev. James Dal- 

 ton, and the former ones are from the neighbourhood of 

 Aberdeen. 



