Mineralogical Contributions — Hobbs. 179 
CONTRIBUTIONS FROM THE MINERALOGICAL LABORATORY 
OF THE UNIVERSITY OF WISCONSIN. 
By William Herbert Hobbs, Madison, Wis., Assisted by others. 
PLATE XI. 
In the following pages have been brought together a 
number of brief statements which it is thought are deserv- 
ing of being placed upon record. Undertaken from time to 
time as material has come to the laboratory they have 
been allowed to wait until collectively they had a value 
which individually would not belong to them. The econ- 
omical and mineralogical work has been carried out in part 
bv the professor in charge of the department, or by his 
students, but generally in collaboration. Credit for work 
is given in connection with the individual contributions. 
a. Analysis of Huebnerite from Dragoon Summit, 
Ariz* by S. V. Peppel. The specimens of this mineral are 
cleavage blades from large hair brown crystals two inches 
or more in length. An analysis of them yielded the fol- 
lowing results : 
SiO=t 1.10 
WO 3 75.10 
MnO 22.87 
FeO 81 
* 99.88 
The re-calculated analysis excludes the silica, which is 
probably included material. This analysis appears below in 
column 1, and in column 11 is given the theoretical com- 
position of pure huebnerite. 
I. II. 
WO 3 76.13 76.6 
MnO 23.15 23.4 
FeO 82 
100.00 100.00 
b. Quartz Crystals from near Las Vegas, N. M. These 
specimens were received from Mrs. A. P. Buck, East Las 
Vegas, N. M. They constitute numerous double-termin- 
ated crystals of clear colorless quartz of great pellucidity 
resembling in habit the Herkimer quartzes from New York 
* This occurrance has been described by W. P. Blake in the Mineral 
Industry, vol. 7, 1899, pp. 720-722. » 
t And oxides of columbium group, if present. 
