: : = : * 
Brace on the Minerals of Litchfield. 351 & = 
some emeralds in the granite. Among some specimens which 
Mr. Weeks of New York, who discovered this locality, was 
so good as to give me, I found a beautiful rose emerald in its 
matrix. It.is a hexaedral prism, about one and a quarter inch 
in diameter, the summit a plane, one of the lateral edges has 
a truncature. About half of the diameter of the prism is free 
from the matrix, and half an inch of the prism. The color 
isa pale rose, rather more transparent than the emerald. 
The color of the mica of the Goshen granite calls to mind 
the lepidolite or lilalite, which (formerly considered as a 
distinct species) has now been united to mica. The lepidolite 
of Rosena is also accompanied by the tourmaline apyre, now 
the red tourmaline. j ; 
Arr. V. Observations on the minerals connected with the Gneiss 
range of Litchfield county, by Mr. Joun P. Brace, of Litch- 
field, onn. eS a 
Tar gneiss formation is the most extensive of any in Litch- 
field county, and embraces a number of very interesting mine- 
rals. It extends east into Hartford county. On the north it 
runs into Massachusetts, though frequently intefrupted by the 
limestone formation, which rests upon it. It-forms the prin- 
cipal, and in many-cases the only rock of the eastern and north- 
eastern sections of the county, and of the towns of Litchfield, 
Goshen, Warren, Cornwall, and Norfolk. In Washington and 
Canaan, it constitutes the rock of the high mountains, and is a 
part of the same range in the other towns, while the valleys 
and the more moderate elevations are covered with limestone. 
The river Housatonic appears to have made its way through 
and Salisbury. In Litchfield commences a range of porphy- 
ritic granite, or porphyritic gneiss, which alternates with aud 
- Gommon gneiss, and in some instances rests upon it. ‘This rock 
