Localities of Minerals. 239 
connexion with hornblende, perfectly pure, except that it 
contains cobalt ore, like the hornblende 6f Monson and 
Chatham. 
In Brimfield, in Massachusetts, the stone wall, near the 
house of Dr. Lincoln, and of the widow of Gen. Eaton, 
abounds in adularia. The feldspar part of a large portion of 
the granite and gneiss of that vicinity, is supplied by the 
most beautiful adularia. The sulphuret of molybdena, also 
is there very common—t is found chiefly, in veins of granite 
which traverse gneiss. 
+ ¥ ¥ % * * 
Localities of Minerals, observed principally in Haddam,* 
tn Connecticut, in Sept. 1819, by Dr. J. W. Wenster. 
Communicated in various letters to the a 
I have discovered a new locality for roumhalia of great 
beauty, and of remarkable regularity of form; it is about 
one mile beyond the rock which Col. Gibbs blasted, some 
years since, for small, short Tourmalin, which rock, is in 
the road, four miles from the inn, at Haddam. ‘The strata 
in this place, are, mica-slate and gneiss, frequently alterna- 
ting, and passing into each other, traversed by veins of gra- 
nite of various size ;—following the beds of these rocks, 
through a thick wood, | observed the tourmalin increase in 
quantity, and size, towards the more elevated part of the 
beds of mica-slate, a blast being made, the rock appeared 
wholly composed of a yellowish granular quartz, and black 
tourmalin, which were thrown out in profusion, being easily 
separated from the granular quartz. Every crystal was per- 
fect, having three lateral planes, and being terminated at 
each extremity with three; the terminal planes set upon the 
lateral. The diameter varies from 1-6 to 1-2 an inch, but 
I afterwards observed some with a diameter of two inches, 
less perfect however. 
In another letter, it is remarked, I have found a new locali-* 
ty of black tourmalins, all doubly ‘acuminated, and none less 
than an inch and a half in length, by one in diameter. 
* Haddam is about twenty miles from the mouth of Connecticut river; 
on its western bank, and abont 100 miles N. E. from New-York. 
