Lead Mines, &c. of Hampshire County, Mass. 243 
hext to the quartz, and frequently passes into it, and when 
the quarts is transparent, forms unusually fin e specimens. 
I traced this mica slate north inte Goshen: Two or three 
miles from Mr. Searl’s, towards Goshen, the mica slate grows 
harder and forms a stratum in another kind of mica slate, the 
whole reposing upon granite. After passing into Goshen, 
it again becomes softer, lying in boulders on the surface, 
which wholly disappear at a place called the Lily Pond. 
Here this mica alternates - with hornblende. Often the red 
vi in the abhi of quartz, id which the mica slate abounds. 
I have often found dark brownish garnets in this mica shite, 
and small garnets, of the usual colour, in great quantities 
Veins and beds of granite, and veins and beds of horns 
blende traverse this rock, but as Professor Hitchcock is about 
to present the public with a particular account of them, I 
omit to describe them. 
Gneiss—green and red, mixed. 
| know nothing of this rock, I have copied it from Prof. 
Hitchcock’s description of the Connecticut Valle ey. 
Micaceous Limestone—deep blue. 
The micaceous limestone seems to occupy the place that. 
granular limestone nes! does. It is called mieaceous 
‘the circumstance that it conta tains mica dissem+ 
inated through it. ~ Along vith the mica is generally a por- 
tion of silex: 
When tested by the acids, a rapid effervescence takes place, 
until the lime is taken af cag a rom fifty to sixty =. oe ; 
of silex and mica. silex is wanting, then 
ca only remains, which pesss washed appears of a clove coloue. 
In other instances, the mica will also be absent, and the 
siduant will be silex, as coarse, very often, as common oie 
ing sand. 
This limestone is usually found in company with mica 
slate, and in this pa is aint in boulders, patches and 
broken strata. In W meee ia stratum is entirely bre~ 
VOL. XIL~—-NO. 2- 
