Minerals in Mica Slate. 



34T 



debted to William Lincoln, Esq. for the specimen, No. 765, in the 

 collection. According to Dr. Emmons the same mineral occurs in 

 Chester. 



The same gentleman has found stilbite, heulandite, analcime, and 

 chabasie, with hexahedral calcareous spar, on mica slate in the same 

 place. I am not aware that these minerals have before been found in 

 this rock; although stilbite occurs in the Alps in granitic rocks. But 

 the others are confined almost exclusively to trap rocks and metallif- 

 erous veins. 



The mineral called anthophyllite, which some able mineralogists 

 yet consider as a doubtful species, is found in many places in the Hoo- 

 sac Mountain range of mica slate. It occurs in fibrous masses, or 

 imperfect prisms, imbedded in the mica slate. In Chesterfield it is 

 associated with sappare and garnets. In Chester it is connected with 

 pyroxene, garnet, and staurotide. It is found also in Blanford in 

 abundance. 



The mineral called Cummingtonite from its locality, (Cumming- 

 ton,) is thought by some mineralogists to be a variety of anthophyl- 

 lite. Prof. Dewey, however, who first described it, regarded it as a 

 variety of epidote. It needs farther examination. It is found in sev- 

 eral places in Cummington, and also in some of the neighboring 

 towns. I have found it likewise in Warwick, on the east side of Con- 

 necticut river. 



It is not uncommon to find a small quantity of sulphur upon the 

 mica slate in a pulverulent state, and proceeding from the decomposi- 

 tion of some sulphuret. But there is no place where it is found in 

 sufficient quantity to be named. 



The anthracite which I consider as connected with mica slate, I 

 have already described. Graphite also occurs in mica slate, west of 

 Connecticut river : as at Cummington, Chester, Worthington, &c. 

 But I know of no interesting localities. The magnetic oxide of iron 

 exists in the same mica slate range, in disseminated octahedra: as in 

 Blanford, Chester, &c. Sulphuret of iron is met with likewise in 

 the same situation. In Heath, some very handsome specimens of cu- 

 bic crystals have been found. In Hawley, it occurs massive in con- 

 siderable quantity, near the junction of the mica and talcose slate. 



On the top of a mountain in Canaan, Ct. there was found, twenty 

 years ago, a small mass of native iron. The mountain is composed 

 of mica slate, Several years ago I visited the spot and was led to the 

 conclusion, that probably a large mass of this mineral might exist 



