PHYSIOGRAPHY. 223 



Garnet. 



Lustre vitreous, inclining to resinous in some varieties, 

 more nearly the latter. Color red, brown, yellow, white, 

 green, black ; except some red colors, none of them are 

 bright. Streak white. Transparent . . . translucent. 



Hardness = 6-5 ... 7-5. Sp. gr. = 3-6 1 5, Grossular ; 

 3-701, Melanite; 3-769, brown, common Garnet ; 3.788, 

 Pyrope ; 4*098, crystals of precious Garnet, Tyrol; 4-125, 

 grains of precious Garnet, Ohlapian ; 4-179, crystals of Al- 

 mandine ; 4*208, crystals of precious Garnet, Haddam. 



Compound Varieties. Massive : composition granular, 

 of various sizes of individuals, and often, even impalpable, 

 easily separated, or strongly coherent ; faces of composition 

 irregularly streaked, uneven or rough. If the composition 

 be impalpable, the fracture becomes uneven and splintery. 

 The composition is sometimes thick lamellar, and bent, the 

 face of composition being pretty smooth. 



1. From the diversity in hardness and specific gravity, which exists 

 among the numerous varieties of Garnet, it is highly probable that the 

 present limits of the species are too wide, and that they include individ- 

 uals which will hereafter be discovered to constitute independent spe- 

 cies. It is not at all likely, however, that discoveries will take place in 

 coincidence with the arbitrary and empirical separation of the species 

 into varieties, as found in the older treatises of mineralogy ; for these 

 are founded almost entirely upon accidental circumstances. These sub- 

 divisions from their present currency in books, require to be noticed. 

 Grossular occurs only in imbedded crystals of the forms of icositetrahe- 

 dron, and combinations of it with the dodecahedron. Its colors are con- 

 fined to asparagus green and mountain green. Pyrencite also occurs 

 only in small blackish, imbedded crystals in limestone. Melanite pos- 

 sesses the form of modification 1, is generally imbedded, and of a velvet- 

 black color. Pyrope occurs only in grains, and is remarkably distinct, 

 from its pure translucency and blood red color, which is not found in any 

 other variety. Among the varieties known under the simple denomina- 

 tion of Garnet, are found every simple form and combination noticed 



