355 Brace on the Minerals of Ldtchjield, 



begins at Mount Prospect, between Litchfield and Warren, and 

 runs through South Farms, Bethlem, and Watertown. The 

 crystals of feldspar in it, are often very perfect. 



The primitive granite, as a rock, is not found, though it lies 

 scattered on the surface in great quantities, and large masses. 

 The graphic granite in this region is often remarkably fine. 

 Mica slate constitutes a considerable part of those rocks that 

 rest on the gneiss, though never found in such elevated situa- 

 tions. The mica slate rocks are always inclined at a great an- 

 gle with the horizon, and follow the direction of the other 

 range. Litchfield village, Che>^nut hill, and great part of Har- 

 wington, are entirely composed of this rock. The Bantum and 

 the Waterbury rivers have their bottoms of it. Some of the 

 brooks entering the Waterbury, have cut their passage through 

 the mica slate, leaving walls of 40 or 60 feet on each side, tra- 

 versed by veins of a very coarse-grained granite, and often 

 much mixed with sulphuret of iron. The slate near Harwing- 

 ton meeting-house contains a great quantity of sulphuret of 

 iron. Mica slate likewise lies on the sides of the gneiss range 

 in Canaan and Salisbury, where it dips under the limestone. 

 Sienite is scattered on the surface in large masses, especially 

 where the porphyritic gneiss is found. Sometimes, however, 

 the masses are so large as to form mountains. Mount Tom, 

 between Litchfield and Washington, is of this nature, being 

 entirely composed of sienite, resting on gneiss. Slaty sienite 

 is frequently found, having a very large proportion of horn- 

 blende. 



The minerals that are found in this region, are much more 

 interesting than its geology. In describing them, I shall con- 

 fine myself to the district east of the limestone range, intending 

 at some future time to investigate and describe the limestone 

 country. 



Carbonate of lime, the granular limestone, is scattered over 

 the whole of this region. It often is found in the cavities of 

 decayed quartz rocks, and contains tremolite and augite. 



Cyanite or Sappar, is found in great quantities, especially in 

 Harwington and Litchfield. A crystalline mass of this was 

 found a few years ago, weighing probably 16 cwt. ; it lay on a 



