36 



PHYSIOGRAPHY. 



Mesotype. 



Fig. 296. 



Faroe. 



Fig. 292. Primary form, surmounted by dihedral sum- 

 mits, e on e= 143 35. Fig. 293. Primary, terminated by 

 four-sided pyramids, e' on e // = 143 35'. e' on e = 142 

 33'. PHILLIPS. Fig. 294. b on b" = 146 23'. PHIL- 

 LIPS. e'2 one"2 = 142 38'. PHILLIPS. Fig. 295. M on 

 /=135 35'. e' or e" on /=109 IS 7 . PHIL. var. Natro- 

 lite.-Fig. 296. e"I on = 162 15'. M on =162 30'. 

 PHILLIPS. 



Cleavage, parallel with M perfect. Fracture- conchoi- 

 dal, uneven. Surface of the replaced lateral edges, striated 

 vertically ; the rest of the faces smooth. 



Lustre vitreous. Color few shades of white, generally 

 greyish or yellowish. Streak white. Transparent . . . 

 translucent. 



Brittle. Hardness = 5-0 . . . 5-5. Sp. gr. = 2-249. 



Compound Varieties. Implanted globular shapes : sur- 

 face drusy, composition columnar. Massive : composition 

 columnar, consisting of delicate, straight, and generally di- 

 vergent individuals, radiating from a centre ; sometimes ag- 

 gregated into angulo-granular masses. Spheroidal shapes, 

 formed in vesicular cavities. 



