Lead Mines, &c. of Hampshire County, Mass. 239 
composes the most precipitous elevations. Here the strata of 
mica slate and the superincumbent rocks seem to be thicker 
and less liable to decomposition ; the same remarks will ap- 
ply as we pass west from Williamsburgh into Chesterfield ; 
though north, in Goshen, the granite is in great quantities, 
normous rounded masses of granite may be seen in this sec- 
tion, wherever granite predominates, lying on the surface in 
vallies, as well as on the highest mountains. Often these 
masses, as in the north-east part of Williamsburgh, are seen 
eighteen or twenty feet in diameter, resting upen a mere patch 
of mica slate. Another, not far distant, reposes upon a gran- 
ite ridge, quite on its summit, so that the rain that falls on one 
side of the boulder runs to the east, while on the other it 
makes off towards the west. Perhaps I ought to mention that 
it is only when the granite forms beds and veins in mica slate, 
or when it lies contiguous to mica slate, that any of the min- 
erals are found; and upon the highest elevation no rock in 
this vicinity is so completely destitute of minerals, except the 
metallic veins, for these are often found in the Alpine dis- 
" tricts. 
Mica Slate—green pale. 
The mica slate of this region consists of several varieties. 
In Williamsburgh, Conway and Whately, it is not much dis- 
posed to stratification, butin Cummington, Goshen and Ches- 
terfield, it becomes distinctly stratified, and abounds in stau- 
rotide. This staurotide is crystalized in all its usual forms, 
and seems to lie between the strata, so that when any large 
quantity of mica slate is disturbed, it usually splits into slabs 
several inches thick, and the staurotide appears on $. 
slabs are much used for hear c a 
: or near 
their junction, it affords excellent grit stones, which have 
been extensively manufactured in Cummington and Chester- 
field. The variety of mica that contains the staurotide, has 
but very little if any quartz associated with it, but the other 
varieties usually have nests of it in profusion. In Chester- 
