116 
Transactions Texas Academy of Science. 
Genth^ F. a. 
Mr. L. iG. Eakins, of the U. iS. Geol. iSurvey, had never been observed in 
this country. (Since it ibeoaime known that the mineral brought from 
Texas by Dr. Foote was gadolinite, large quantities have been obtained, 
some in crystals, weighing from seven to eleven pounds. I am indebted 
to Mr. W. Farl Hidden for some from Llano county, Texas, and give in 
the following the results of my analyses of this as iwell as that received 
from Dr. Foote. 
“It has a black color ; in thin splinters it is translucent with a dark 
bottle-green color; the fine powder is greenish-gray; fracture conehoidal to 
splintery. iSp. gr.=^4.2(>l (Burnet county) to 4.254 (Llano county). 
•» -» * 
“The Texas gadolinite is altered into a brownish-red mineral of waxy 
lustre, finally into a reddish or yellowish-brown earthy substance. Neither 
could be obtained in a state of purity, but I will give below a partial analy- 
sis of the former., Tengerite (?) or yttrium carbonate in thin, white 
crystalline incrustations is tfound between the cracks of the gadolinite. 
There was only enough obtainable to show their composition by qualitative 
tests. 
* * * ' * -:s- * ■Jt 
“The following results were obtained ; 
I. BURNET COUNTY. II. LLANO COUNTY. 
a 
h 
a 
b 
Si O 2 
22.87*) 
23.40*) 
22.80 
22.92 
AI 2 O 3 
0.28 
0.33 
0.31 
0.29 
Cea O 3 t) 
2.65 
2.76 
2.66 
2.85 
(Di, La )2 O 3 
5 22 
5 17 
5.01 
5.33 
(Y, Er), O 3 
44.35 
44.65 
44.45 
44.30 
Mn 0 
0.22 
not det. 
0.18 
not det. 
Fe 0 
13.69*) 
13.58 
12.93 
13.03 
Be 0 
9.24 
9.32 
9.19 
9.34 
Mg 0 
0.07 
0.08 
O.Tl 
not det. 
Ca 0 
0.64 
0.54 
0.71 
0.78. 
Nag 0 
0.20 
not det. 
0.23 
not det. 
Ka 0 
0.15 
a u 
0.12 
u u 
Ignition 
0.72 
U il 
0.79 
u u 
Insoluble in dil. 
Ha SO 4 
u u 
0.93 
0.92 
100.30 
100.42 
includes the Fe^Og and iSiO^, insoluble in dilute sulphuric acid 
“t Mr. L. G. Faldns informed me that he had found Th O 2 in the Texas 
gadolinite. As I had not tested for it, I examined the ceric oxide, left 
from the four analyses, and found it to contain 3.22 per cent, of Th O 2 . 
“decomposed gadolinite from llano county. 
Spec, gray 
Ignition 
Quartz 
Si O, 
(Ce, Di, La, Y, Er)2 O 
I 60 Oo 
Mn O 
Ca O. 
3.592' 
9.30 
1.03 
22.11 
39.20 
14.53 
6.03 
0.22 
5.58” 
