DESCRIPTIVE MINERALOGY. 
368 
scratch glass. Before the blowpipe, it foams up at once, becomes brown, and by a continued 
heat is brought to the state of a black opaque scoria. Its specific gravity is 2.41, and it con¬ 
tains silica 78.25, alumina 12.75, alkali 8.00, together with some oxide of iron and water.* 
SPODUMENE. 
If rom the Greek tfctoSos, ashes ; in allusion to the change which it undergoes before the blowpipe.] 
Spodumene. Cleaveland, Phillips, Thomson and Shepard. — Triphane. Homy and Pendant. — Prismatic Spodu- 
mene. Jameson. — Prismatischer Triphan-Spath. Mohs. 
Fig. 384. 
Description. Colour greenish white and greyish green. Streak 
white. It occurs massive and in large granular concretions. Cleaves 
in the direction of an oblique rhombic prism, which is its primary 
form. Fig. 384. M on M/ 93°. Fracture uneven. Lustre shining 
and pearly. Translucent. Very easily frangible. Hardness from 6.5 
to 7.0. Specific gravity from 3.11 to 3.19. Before the blowpipe, 
it swells to a foliated reddish yellow mass, which on the smallest agi¬ 
tation falls to powder. The outermost portions fuse into small glassy 
globules {Thomson). 
Composition. Silica 66.49, alumina 25.30, lithia 8.85, oxide of iron 1.45 {Arfwedson). 
Geological Situation. It occurs in primitive rocks, especially in granite. 
Saratoga County. Spodumene was said by Dr. Steele to occur near Saratoga Springs, 
associated with reddish feldspar, black mica and quartz ; but it may be that some other mine¬ 
ral has been mistaken for this, as I am not aware that it has been found by any other mine¬ 
ralogist. It occurs at Goshen, Massachusetts, and in the towns of Chesterfield and Sterling 
in that State. It resembles pyroxene, but can easily be distinguished by its behaviour before 
the blowpipe. 
PYROPHYLLITE. 
[From the Greek rfug, fire , and cpuXXov, a leaf.] 
Pyrophyllite. Phillips, Thomson, and Mohs (App.) 
Description. Colour white or greenish white. It occurs in fibrous radiating masses, and 
small elongated prisms whose form has not been determined. Cleavage indistinct, rectangu¬ 
lar. Lustre pearly. Hardness 1.5. Specific gravity 2.80. Before the blowpipe, it spreads 
out. in a fan-like shape, and increases to twenty times its former bulk ; with borax, it forms 
a green transparent glass. When heated with nitrate of cobalt, it assumes a blue colour. 
* Troost. Journal of the Academy of Natural Sciences of Philadelphia . V. 55. 
