92 
RIO GRANDE COAL FIELDS OF TEXAS. 
[bull. 164. 
nate present was removed by treating the rock powder on the water 
bath for ten minutes with diluted hydrochloric acid (1-10). The result 
of the analysis is found under Table I. 
For comparison, the average of five analyses of pantellerite from 
Pantelleria 1 is placed under Table II, and under Table III is placed 
the average of paisanite from Mosquez Canyon. 2 
I. Analysis of quartz-pantellerite from Presidio County, Texas. 
Constituent. 
Si0 2 
Ti0 2 
A1 2 3 
Fe 2 3 
FeO 
MnO 
CaO 
BaO 
SrO 
MgO 
K 2 
Na 2 
Li 2 
Water 100 Q 
WaterlOO [ 
S0 3 
PA 
co 2 
Total... 
Per cent. 
68. 71 
.21 
13.45 
5.31 
.75 
.14 
.96 
None. 
None. 
.19 
5. 51 
4.63 
None. 
.13 
.36 
.05 
.04 
None. 
100. 44 
iH. Foerstner: Zeitsch. fur Krystallog., Vol. VIII, 1884, p. 125. 
2 A. Osann, Beitrtige zur Geologie und Petrographie der Apache (Davis) Mountains, Westtexas: Min. 
und Pctrogr. Mitth., Vol. XV, 1895, p. 439. 
