Talcosc Slate. , 23 



Mica Slate. 



This rock is generally more uneven or tortuous in the structure of 

 its layers, than any rock in the State. But, like gneiss, its layers are 

 sometimes remarkable for their regularity. It then forms an admira- 

 ble stone for flagging, for hearths, and for situations where there is 

 an exposure to a moderate degree of heat. The variety that occurs 

 in Goshen and Chesterfield, Hampshire County, is perhaps the best 

 in the State for these purposes ; and in these places, particularly in 

 Goshen, it is quarried to a considerable extent. In some cases this 

 rock approaches so near to argillaceous, or roof-slate, that it is employ- 

 ed for common gravestones. In Halifax, Vt, there is a quarry of 

 this character ; and, I believe, also in Chesterfield Mass. Sometimes 

 it forms excellent whetstones ; and from the quarries in Enfield and 

 Norwich, large quantities are obtained and extensively used. 



Talcose Slate. 



The principle value of this rock, in an economical point of view, is 

 derived from its power of resisting high degrees of heat. The great- 

 er the proportion of talc in its composition, the more valuable is it in 

 this respect. A very fine stone of this description, for the lining of 

 furnaces, is quarried in Stafford Ct., and it is employed to some ex- 

 tent in the furnaces in Massachusetts. I do not know of any quarry 

 of this kind in our own state ; but undoubtedly such might be opened, 

 since almost every variety of talcose slate exists here. Indeed, I 

 am informed by the Rev. Mr. Colton, of Amherst Academy, that tal- 

 cose slate, equal to that in Stafford, may be dug in Monson. 



In Plainfield and Hawley a variety of talcose slate occurs, in which 

 are disseminated numerous crystals of black hornblende. The talc 

 is green and the quartz white, and the rock admits of a polish. 

 Sometime the talc almost disappears ; and then we have a white base 

 with black crystal imbedded. In short, I feel satisfied that this rock 

 would form a beautiful ornamental stone, if wrought into tables, urns, 

 chimney pieces, &c, &c. But of this others can judge from the 

 specimens which I shall place in the collection already referred to. 

 Large blocks of it may be obtained, which would be very firm 

 throughout. 



Limestone. 



Next to our granite and gneiss, this is the most valuable rock in 



