J.D, Whitney on Minerals of the Lake Superior region. 13 
flesh-red color, owing to the noone of a minute quantity of 
suboxyd of copper diffused through it 
The veinstone of the Ontonagon region had seemed to be 
uite destitute of this mineral, and it was not until last summer 
that it was discovered by me in that district. At the Minnesota 
mine, among the vein-stuff thrown out, some singular nodules 
were observed looking like rusty cannon balls. On breakin 
one of these open and examining it, it was anad to ‘ datholite, 
in a singular and hitherto unobserved form. 
The mineral is quite compact, breaking with a conchoidal 
fracture, porstey white, opaque, and resembling in its phys 
cal character the purest and most close-grained marble. 
hardness = 4:5; specific gravity 2°983. 
An analysis of this mineral by Prof. C. F. Chandler, gave the 
following results 
Silica - - - - 3741 
Oxyd of iron and Sa - - - "35 
‘ ‘ : . 85:11 
Bora acid (by loss), - - : - - 21:40 
Wate siya . - - 573 
100°00 
hich: 
17 miles west of Marquette, may be inferred from the followin; 
analyses recently made of specimens from the three a 
i he 
? ? ? 
ply of ore of the same quality could be obtained, without reject- 
ing any considerable amount of the stuff which is quarried out, 
were it desirable to ship a perfectly pure ore. The average 
of the ore shipped would, in point of fact, fall _ little 
low that given et e on analyses. 
MIL. 
%. ~ ae oe (eae 
“a. . 
Insoluble, 1:02 80 “4 792 796. 199 205 
ems 69°41 7022 69°96 sees 6401 6881 
XV traces of 
en ‘Leos 28:98 2950 2766 28-03 29°20 
I. is ore from the Jackson, 1. fom the Cleveland, and mu. 
from the Burt or Lake Superior mountain. The fra ragments an- 
bs sie were, in each case, roken from the different portions of 
