50: 
pointed piece will scratch glass, and may be scratched by a 
steel point upon the large faces of its lamine; but not upon 
the lateral ones. The refraction is simple. The primitive 
form is an oblique quadrangular prism, of which one plane 
is inclined upon the other, at an angle of about 103°.— 
Integrant molecules the same. Infusible without addition. 
Seldom shows any determined crystal, at least among 
English specimens. 
Analyses by Saussure, by Lauguier. 
VERBAL oo) BT hs ey ooo | ee 
IGA eens BO eels wh ee ee 
Weta Ho Nay inal eae y Gum Rae 
Nig raest e754 seh ou oon 
Oxide of ron 9 6 |. cal causa ae Bee 
Water ergy oT Re OC? Ses lien 
