A. Minerals opaque 
N^aine. 
die in Comp . and 
reactions. 
Specif. 
Gray. 
Crys- 
tal 
Cleav- 
age. 
Usual combina- 
tions and form of 
Sections. 
Tioins. 
I. Mag- 
netite. 
Fe.. 0^ = 
Fe’0-F[Fe,J 0,. 
soluble in FI Cl. 
4.9- 
5 - 
I 
In the 
plane 
I. 
Granular and 
I. Quadratic and 
Triangular. 
In the 
plane i. 
i 
i 
2. Titan- 
ic Magne ■ 
tite. 
leu pj 
Only distinguish- 
able by chem. 
analysis. 
4.8- 
5-1 
I 
I and granu’ar. 
as above 
3. Pyrite. 
Fe S2 
Soluble in nitric 
acid separating 
sulphur. 
4.9- 
5 - 2 - 
I 
H 
[i-2j 
Regular hexa- 
gons and penta- 
gons. 
Interpene- 
trating 
twins 
[i-2.] 
4. Titan- 
ic Iron. 
Fe Ti 0 .. + 
-KFe2 
Soluble in H Cl 
with dif. With 
salt of phosph. 
gives reaction for 
Ti. 
4. qb- 
5-21 
Hex. 
R and 
OR. 
con- 
choi- 
dal 
frac- 
ture. 
Tabular R.oR 
also R, - 2 R 
and granular 
grains elongate 
rather than 
rounded. 
Sections chiefly 
hexag. elongate. 
In zic-zack ed or 
reticulated forms. 
iAxes par- 
allel, Poly- 
synthetic 
twins in 
R. 
1 
5 . Graph 
ite 
(and Bitu- 
men.) 
C. 
Bitumenous 
black rocks, be- 
coming gray on 
heating. 
1.9- 
2-3 
Flex. 
0 
Very rare, in 
thin hexagonal 
plates and irreg- 
ular scales. 
6. Pyrr- 
hotitc. 
See also 
Cliro-'] b 
mite, e 
Pleo- I y 
nast, 0 
Spec • 1 n 
ular 1 d 
Iron. J 
Fe S , 
n n T I 
4-54 
4.64 
Hex. 
• 
Irregularly gran- 
ular. 
