ij6 



£ARTHS. AGGREGATE. 59. Granites. 



ORDER VII. AGGREGATE. 



Compofed of a mixture of the former orders. 



59. GRANITES. Confifting of parts, moftly in 

 the form of cryftals, cohering without any inter- 

 inediace cement, and mixed without any deter- 

 minate order j generally of a granular texture, 

 hard and durable, and admitting a fine polifh: 

 conftituting the principal material and nucleus of 

 ptimitive lofty mountains. 



simplex. Confifting of feldfpar and quartz. 



Saxum morenfe. Syst. nat. xii. 3. p, 75. n. 14. 



Found in the Siihaudic^ Snxiifsy Siberiany and Scotch mountains, 

 and detached near Geneva: the component parts vary as to 

 their predomination, but the particles of feldfpar are fome- 

 times fo combined with tranfparent quartz as to refemble 

 Syriac letters. 



genuinus. Confiding of feldfpar, quartz, and mica. 



Saxum fpatofum. Syst. nat. xii. 3, p. 76. n, 19. 



Saxum quarzo, &c. JVall. Jyji. 1. p. 407. 



Gran it. Schmeifier mineral, i. /. 308. 



Granite. Kimvan fnineral. l^p. 338. Thomfon chem, \. p, 130, 



The moft common kind of granite, and is found in primitive 

 and fometimes in kcondary mountains in moft parts of the 

 globe, in innumerable varieties of hardnefs, proportion, dif- 

 tribution and colour of parts : fometimes it is found mixed 

 with other minerals, as fhorl, hornblend, cryftals of garner, 

 fteatite, and alumina: it melts in a high degree of heat, 

 leaving however the quartz unaltered : the feldlpar is often 

 fiefh-colour ; the quarrz generally white, rarely greenifh : 

 it take? a very high polifh, and on this account has for many 

 ages been uled in the architecture of columns, palaces, 

 churches, and various ornaments. 



Syenites^ Confifting of feldfpar, quartz, and hornblend. 

 Syenites. Blin. Hiji. rnund^ /. 36, ch. 8 ? 

 Sienit, Schmei/ser miner, l. pt 309. 

 Sienite. Kirivan min. i./, 341, Ibomfon chem» ^» p> I'^l^ 



