132 CONTRIBUTIONS TO MINERALOGY. [bull. 262 
14. BOURNONITE. 
An analysis of massive bournonite from Bogg's mine, Big Bug dis- 
trict, Yavapai County, Ariz., furnished for analysis by Prof. C. 
Palache, yielded the figures given below. 
S 20.04 
As 2. 81 
Sb 18. 99 
Pb 40.21 
Cu 15.12 
Fe 35 
Zn 35 
Mn trace 
Insoluble 1. 67 
99.54 
15. ANHYDRITE. 
A deposit of crystallized anhydrite occurs in Texas, the exact locality 
of which is not known. The crystals are small, reaching a maximum! 
of 1 mm. in length, and are tabular parallel to the macropinacoid. 
The base is present as a long, narrow face. 
The clinopinacoid is probably present, but 
the zone of brachydomes is very rounded 
and striated, no sharp faces occurring in 
this zone. Under the microscope the crys- 
tals show that the axial plane is parallel to 
Fig. 10.— Anhydrite. ... 
^ = {010} and the acute bisectrix is normal 
to «={l00}. The interference figure is about as large as that of mus- 
covite and is positive. An anatysis was made of the mineral, to leave 
no doubt as to its identity. 
CaO 41. 01 
S0 3 58.87 
Ign '. 22 
Insoluble 06 
100. 16 
16. GLiAUCODOT. 
A sample of cobalt ore from the Standard Consolidfited gold mine, 
Sumpter, Oreg., consists of glaucodot, with pyrite and perhaps other 
sulphides, in a dark silicate rock. Imperfect crystals are abundant, 
though they usually show but one or two faces. Much of the ore is 
massive, and it is practicall} 7 impossible to determine whether it is all 
glaucodot or in part cobaltite. One crystal was measured. The 
small crystal (about 1 mm. long) is orthorhombic, and shows the fol- 
lowing forms: ?n={ll0}, 5={010}, ^={101}, and a very much striated 
brachydome zone in which the following forms are probably present: 
{014}, {013}, {012}. 
