PHYSIOGRAPHY. 97 



Peridot. 



Irregular forms, grains. 



Cleavage, parallel with P easily obtained, sometimes 

 traces of T. Fracture conchoidal. Surface, the faces of 

 the prism streaked horizontally, those of the rest of the 

 faces, smooth and even. The grains possess an uneven sur- 

 face. 



Lustre vitreous. Color various shades of green, as 

 pistachio-green, olive-green, nearly asparagus-green and 

 grass-green, sometimes passing into brown. Streak white. 

 Transparent . . . translucent. 



Hardness =6*5 ... 7*0. Sp. gr. = 3-441, a crystallized 

 variety. 



Compound Varieties. Irregular spheroidal masses, im- 

 bedded in rocks : composition granular, individuals easily 

 separated, faces of composition uneven and rough. 



1. Before the blow-pipe, it assumes a darker color, but does not melt 

 or lose its transparency. It loses its color in nitric acid. Varieties of 

 the present species may be produced artificially, by mingling the constit- 

 uents in the requisite proportions, and exposing them to a high tempera- 

 ture. 



2. .Analysis. 



By KT.APROTH By KI.APROTH. I3y SHEPARD. By KLAPROTH. 

 var. Chrysolite, var. Chrysolite, var. Chrysolite, var. Olivine. 

 fr. meteoric iron. fr. meteoric stone. 



Silica 

 Magnesia 

 Ox. of iron 

 Lime 



Soda, } 



Ox. chrome, & V 0-00 . 0-00 . 557 . 0-00 



Sulphur 3 



3. The original repository of the implanted crystals of Peridot is not 

 known : they are said to come from Upper Egypt, and are frequently 

 brought to Europe by way of Constantinople. Less distinct crystals and 

 imbedded grains are found in lava, in various kinds of basalt, &c., as in 

 the neighborhood of Vesuvius, in Saxony, Bohemia, Silesia, Hungary, 



VOL. II. 9 



