b. Double refraction 
A'ame. 
CJiem. Comp, and 
reactions. 
Specif. 
Grav. 
Cleav- 
age. 
Usual combi- 
nafs and forin 
of the Sections. 
Tzvins. 
Char, and 
amp of the 
dpi. refract 
Polar- 
ization 
Colors. 
Color and 
Amount of 
refraction. 
4. Ana- 
tase. 
i 
1 
As in rutile. 
3-83- 
3-93 
0 and 
I . 
Apex I. 
As in 
rutile. 
Like 
rutile. 
Dark, 
lavender 
blue. 
5. Ale- 
Jonite 
g'P- 
a Mejo- 
nite. 
b. Sea- 
polite. 
Ca,; (Al„) Si;, 
R3 (Ag Si,; 0,1 
(R=Ca.Mg No,) 
Soluble in H Cl 
separating pulver- 
ent Si 0., 
2-734- 
2-737- 
2.63- 
2-79 
Com- 
plete. 
i-i 
Crystals I. i-i. 
I and large 
grains or long 
columnar in- 
dividuals. 
1 _ 
Double . 
refraction 
negative, 
rather 
strong. 
1.594- 
I 597 
1.558- 
1.561 
Colorless, 
white. 
w^i.566 
£==1-545 
i 
c. Cou- 
sera- 
nite 
and 
Dipyre 
Similar to scapo- 
lite; rich in alka- 
lies, H., 0 . 
Unaffected or but 
little affected by 
acids. 
2.69-2.76 
(2.bi3) 
2. 62-2. 68 
i-i. 
frac- 
ture in 
0. 
Long columns^ 
I. i-i. 
rounded or 
frayed out at 
the end. 
1 
1 
1 
i 
As in 
scapolite, 
rather 
strong. 
Rather 
bril- 
liant. 
Bluish, in 
sections, 
colorless, 
pelucid; 
becomes 
black from 
inclusions 
6^=1.558 
£=i-,543 
d. Me- 
[ lilite. 
(Ca, Mg. Na,) „ 
(AI2 Fe2 )2 
Si;, 0 ;j„ 
easily soluble in 
H Cl with sepa- 
ration of gelati- 
nous silica. 
2.90-2.95 
I 
j 

Paral- 
: lei 
iO and 
1 I- 
■ 
i 
Almost always 
in crystals; 
thin plates 
predominat- 
ingly 0 . I . 
i -i 
Irregular 
grains. Sec- 
tions mostly 
linear, rect- 
angular or 
rarely 
rounded. 
Rarely 
inter- 
pene- 
trating 
twins 
with 
the 
princi- 
pal 
axes at 
right 
angles. 
Feeble. 
Not 
very 
bril- 
liant, if 
jyellov\- 
and fi- 
brous it 
affords 
the col- 
oration 
of an 
aggre- 
ate, if 
color- 
less the 
polari- 
zation 
colors 
are 
bluish 
gray. 
Usually 
citron yel- 
low, honey 
yellow 
colorless, 
to yellow- 
ish white. 
