22 Localities of Minerals in Massachusetts. 
Oride of Manganese nied 
‘The siliceous oxide of m anganese exists in einnied- 
ton in immense quantity lying in bowlders in the stone 
walls, half a mile west of the congregational meeting- 
house, on the farm of Mr. Packard. ‘The masses vary 
from a few inches to several feet in diameter, and are uni- 
formly of a coal black on their surface, being covered with 
the compact oxide of manganese, from a mere line to two 
or three inches in thickness. On breaking open these un- 
sightly masses, the interior is disclosed of a beautiful rose 
red, sometimes rs ssrB sometimes distinctly, foliated, 
ad much resembling rose quartz, except in being of a 
deeper colour. I doubt not it would be an easy matter to 
collect at this locality fifty tons of this mineral ; so that 
there is no danger of its being exhausted. I could not 
find the ores in place, though from the appearance of some 
miami I have little doubt they ‘if this a bed in mica-slate, 
s not the fact that the masses s siliceous oxide of 
manganese, at this locality, are always covered with a coat~ 
ing of the compact oxide, worthy of the notice of the min- 
eralogist ? Does it not lead to the conclusion, that the latter is 
oduced by the action of the atmosphere upon the former ? 
Veins of the compact oxide do indeed penetrate to the centre 
of the masses; but they appear uniformly to follow cracks, or 
_ interstices, into which the air had penetrated. Mr. Bryant, 
who lives near the spot, pointed out to me a specimen, 
which had been broken a year or two since, and which, by 
simple exposure to the weather since that time, had alrea- 
dy Gecoene coated by a thin pellicle of the black oxide. 
Carbonate of Tron. 
‘This mineral, as might be expected, occurs at the same 
; but not notice much of it. Its colours are 
pale’ setbow; basbicle to brown, reddish brown, and even 
blackish brown. It occurs in laminated masses, not large, 
“ae perhaps passes into. brown spar. Carbonate of Tron 
is found also in abundance i in Plymouth, Vermont. 
