10 
index for quercyite is given by Lacroix as 1 *608. The figures obtained for 
the British Columbia mineral are quite different, and are as follows: 
a =1-613 ± 0-002; j8=l-626± 0-002; y=l-629± 0*002. 
Thus the birefringence is slightly higher than that of dahllite or francolite. 
The Canadian quercyite is distinctly biaxial with 2V = 5° to 10°. The 
specific gravity of French quercyite varies from 2*83 to 2*87, whereas 
the density of Canadian quercyite is 3*04, a figure closer to the gravity of 
pure francolite than to the original quercyite. The British Columbia 
quercyite has a hardness of 4*5. It does not fuse under the blowpipe, but 
decrepitates violently, emitting a perceptible amount of volatile matter. 
Material carefully prepared by the writer was analysed in duplicate 
by E. A. Thompson of the Mines Branch. The average of these two 
analyses is given below in column 1 ; the other three analyses are quoted 
from Lacroix’s “Mineralogy of France.” 
Analysis of Quercyite 
— 
1 
2 
3 
4 
34-96 
50-22 
1-90 
0-12 
0-12 
0-60 
0-62 
1-83 
5-45 
4-20 
0-19 
0-82 
37-60 
51-85 
36-60 
50-45 
37-75 
52-50 
0-85a 
5-70 
3-20 
CaO 
FeO . . . , 
Fe*0*.,... 
FesOa \. . . . . . 
1-30 
Mn*0*. . 
Al®Oj / 
AlsO*. ... 
MgO . 
: 
HsO + 105 
i-50 
4 00 
4-80 
0-83 
4-62 
6 00 
SiO*. 
c. 
Less O equiv. toF... 
101-03 
0-77 
100-26 
99-75 
99-80 
100-00 
No. 1 (Cr, Na, K, Sn, Ba, Ti, SO*, Cl, and WO» were absent.) 
Analysis 2. From Mouillac, T am-et-G aronne , France. 
Analysis 3. From Mouillac, T am-et-G aronne, France. 
Analysis 4. From Belrnez, Cordova, Spain. 
a — Contains a little F. 
From analyses 1 to 4 given above, the following molecular ratios are 
obtained : 
Molecular Ratios, Quercyite Analyses 
— 
1 
2 
3 
4 
Average 
CaO 
0-896 
0-926 
0-900 
0-937 
PjOs. 
0-246 
0-264 
0-257 
0-265 
F...., 
0-096 
0-GS0 
0 043 
CO*., 
0-124 
0-090 
0-105 
0-130 
H*0.. 
0-233 
0-270 
0-333 
0-180 
CaO.... 
100 
100 
100 
100 
100 
P*0».. 
27 
28 
28 
27 
27* 
F 
10 
9 
5 
8 
CO* 
13 
10 
10 
13 
111 
H*0 
26 
28 
37 
19 
27* 
