104 PHYSIOGRAPHY. 



Picrolite. 



PICROLTTE. Fibrous Atelene Picrosmine 

 Massive : composition thin columnar, consisting of straigh 



and delicate individuals. Fracture uneven, rarely splintery 

 Lustre vitreous : in very thin individuals, satiny. Color 



some shade of green or greenish-white, greenish-grey 



mountain green, oil-green, leek-green, and blackish-green. 



Translucent on the edges. 



Brittle, except in the finest fibres, when it is flexible, 



Hardness =3-0 . . . 4-0. Sp. gr. =2-59.1. 



1. When heated before the blow-pipe in thin fragments, it coils up a 

 the extremity, and fuses into an opake, white mass. With phosphoric 

 salt, it melts into a transparent glass, with the exception of a skeleton ol 

 silica. 



2. Analysis. 

 BY ALMROTH. 



Silica 40-04 



Magnesia ....... 38-80 



Water . 9-08 



Protoxide of iron 8-28 



Carbonic acid 4-70 



3. This species, as first described by HAUSMANN, (with no othi 

 properties than its columnar composition, a faint pearly lustre, a leel 

 green, to yellow color, streak a little shining, and hardness from 3-0 . . 

 6-0,) was quoted as forming irregular veins in the beds of Magnetic 

 Iron of Taberg and Nordmayken in Sweden, and as occurring a 

 Reichenstein in Silesia. As described above, it has several localities ir 

 the United States. ID particular, it occurs in large masses, which exis 

 in irregular seams in the verd antique marble of West Haven and Mil- 

 ford, (Conn.) ; at which places the individuals are coarse, and sometimes 

 a little curved. At Weathersfield in Vermont, it forms numerous nar- 

 row veins through a serpentine rock, which also contains Dolomite, th( 

 individuals being very thin, and exhibiting a satiny lustre. At Kellj 

 Vale, in Vermont, also, it is found in somewhat wider veins, coarsel) 

 columnar, of a light oil-green color, and containing much yellow.* 



* The foregoing American varieties afforded the description above giv- 

 en, respecting color, composition, specific gravity, hardness, and beha- 

 vior before the blow-pipe. These also lost 13 04 p. c. wt, on calcination 



