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APPENDIX 
of veins by molten matter from beneath, supports the same view, and in this case we see 
the hill of breccia and beneath the vein. It would be interesting, could we establish this 
view of the origin of this peculiar rock. This is quite apparent, when we take into con¬ 
sideration the multitude of these brecciated beds along the eastern limits of the Taconic 
system. They range nearly in a line running through Berkshire county, at the western 
base of the Green mountains, and northwardly into Vermont. Tire question will not fail 
to suggest itself to every inquisitive mind, whether these beds are all connected with veins 
beneath. The question of their origin then assumes a practical importance, and is worthy 
of being followed very carefully out to its full solution. If such a result should be ob¬ 
tained, it will open an inexhaustible source for this kind of ore, which is usually of an 
excellent quality, and easy to smelt. It is, however, proper to state, that the quartz lock 
in which this vein appears in Adams, is a hard rock to blast; and it is possible that the 
expenses, from this cause alone, of obtaining the ore, might be so great as to render these 
veins useless. Much undoubtedly would depend on their width : if wide enough to be 
quarried without rendering it necessary to blast the rock itself, then there would be no 
difficulty in working these veins. The matter must remain undecided, until some of them 
are opened and worked. 
The position of the veins of limonite adjacent to the primary of the Green mountains, is 
analogous to those of Jefferson and St. Lawrence counties, where the specular iron, both 
in its earthy and crystalline state, appears in veins connected both with the primary below 
and the potsdam sandstone above. In both cases the veins are found only in thin parts of 
these sandstones, and near or adjacent to primary rocks. It is curious to observe, how¬ 
ever, that in one case, the iron is in a state of peroxide pretty uniformly, forming the 
specular oxide, and I believe without exception ; and in the other, it is the hydrous per¬ 
oxide, constituting the mineral called limonite. The former does not form a breccia with 
the potsdam sandstone, and we find a different association of minerals also in each of these 
cases. With the specular ore, we find serpentine, barytes, crystals of quartz, cacoxenite, 
etc.; and with the latter, gibbsite, allophane, manganese, and white carbonate of iron. 
The gibbsite and allophane are minerals of secondary formation, and, so far as observation 
has extended, they are not found in the veins of limonite. Distinct and irregular veins, 
however, of the latter mineral, are not new to mineralogists. Thus a few veins, a foot in 
width, traverse the gneiss of Dekalb in St. Lawrence county. The same occurs near 
Crownpoint, and indeed a thin vein has been found in the calciferous sandstone in Georgia 
(Vermont). A practical remark is suggested by the position of these veins, namely, that 
their place is near or adjacent to primary or igneous rocks ; or it is here that they are 
accessible, and reach the surface, though it may not be at all improbable that they are 
frequent in other situations, but concealed by a great thickness of sedimentary materials. 
I take this opportunity to add a few additional remarks on the quartz rock itself. Some 
geologists of eminence have maintained that this rock belongs strictly to the Primary sys¬ 
tem ; that it is of the era and age of the gneiss, with which it is sometimes apparently 
