Ore of Cobalt and Manganese. 283 
5. Notice of a singular ore of Cobalt and Manganese ; by 
H.H. Haypen, of Baltimore, in a letter to the Editor. 
I have now a circumstance to mention, which I consider 
of avery novel and singular nature. A few days since a 
gentleman returning from the country into Baltimore, at the 
distance of two miles, observed some men digging for sand 
by the road side. Among the sand thrown out of the pit he 
observed some masses that had the appearance of ore. He 
brought some of it to town, when on examination, it was 
found to contain a considerable proportion of oxid of cobalt, 
combined with Manganese. E ited by no com 
gree of curiosity, I yesterday, in company with Mr. 
visited the locality of this substance. We found the pit 
abovementioned by the road side, and which was opened 
I believe, for the purpose of obtaining plastering sand. The 
hole or pit was sunk to the depth of about ten feet—the sides 
presenting to view much of the variety of stratification that 
occurs in almost every part of our alluvial region, and in 
which this pit is sunk. On examination we found the mine- 
ral above mentioned, to occur upon or between two veins or 
strata of hard ferruginous sand, and at different heights—to 
one or the other of these it adheres. ‘There were a number 
of masses upon the surface, at the mouth of the pit, however, 
that did not appear to have had any connection with 
ferruginous strata. 
is substance occurs in masses of various sizes, and ap- 
pears to be made up of grains of sand firmly cemented to- 
gether by the cobalt and manganese ; so much so as to ren- 
der its specific gravity perceptibly greater than that of 
common substances. ‘The masses are somewhat spherical 
with surfaces inclining to the stalactitic form. The colour 
is black, inclining to a deep blue. “ 
I know of no instance in which cobalt and manganese oc- 
eur in this form and manner. It is true that Klaproth in his 
Essays, mentions a mineral in which these two su 
ate combined, and which is not described in any other work 
that I know of. But the substance under consideration ap- 
pears to me to be an anomaly in the mineral kingdom, at 
least so far as respects its locality. It is, as before, in a per- 
fect alluvial bank, surrounded on all sides by strata of fine 
