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160 Outlines of the Mineralogy and Geology 



SPECIES \lll.—COMJ\IOJ\^ GAILYET. 



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Common Garnet, Cleaveland^p. 293. Idem, Jameson^xoL i. p. 69. Idem^ 

 JUkitij p. £40. 



JStXternal Characters, 



Its colours are red and brown. Of red, it occurs venous 

 blood red, and brownish red ; of brown, reddish brown. 

 Its lustre is shining and resino-vitreous. 

 It is slightly translucent at the edges, and some small crys- 



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tals are transparent. 



It occurs crystallized in, 



1. A dodecaedrou, the solid angles of which are frefj[uently 

 truncated. 



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2. A double eight-sided pyramid accuminated by four plants, 

 the lateral planes of the one being set on the lateral planes of the 



V 



other^ and the acuminating planes set on the alternate and dif- 

 ferent edges of the pyramids ; the whole presenting a figure 



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hounded by twenty four unequal trapezoidal faces. The surface 

 of the crystals is smooth and shinning ; and sometimes slightly 

 diagonally striated. The crystals are small and middle sized 

 and all around crystallized. They are often imbedded in each 

 other, and the double eight-sided pyramids sometimes easily sep- 

 arate at their bases. 



Its streak is reddish white. 



It is hard 5 some specimens scratch quartz. 



The fracture is foliated ; and imperfectly small conchoidal ; 

 the cross fracture is fine grained uneven. 



It is brittle. 



It is easily frangible. 



The fragments are tabular and splintery. 



; 





Its specifick gravity is from about 4.06 to 4?.S0. 



am^^ 



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