Minerals in Serpentine. 



371 



At one of the limestone quarries in Littleton, I observed that small 

 masses of green serpentine were disseminated in the rock. (No. 489.) 



The only remaining deposite of serpentine within the limits of the 

 map, is in Newport, Rhode Island. And under graywacke I have 

 already given so full a description of the situation and characters of 

 this rock that any thing more seems unnecessary in this place. From 

 that account it is obvious that this serpentine belongs to a much later 

 geological epoch than any which I have described ; probably as late 

 as the graywacke ; and if there be any example in the region embrac- 

 ed by the map, where the serpentine occurs in a vein of considerable 

 size, Newport is the locality. 



Mineral Contents. 



Serpentine bears a strong analogy to steatite in its mineral contents 

 as well as in several other respects. Nearly all the simple minerals 

 that have been described as existing in our steatite, occur also in the 

 serpentine. The beautiful green amianthus of Newbury has already 

 been mentioned and the asbestus of Pelham ; as well as the amphibo- 

 lic mineral, (probably actynolite,) in Westfield. At the latter place 

 well characterized actynolite occurs ; and according to Mr. Emerson 

 Davis, anthophyllite also. Here is likewise found a mineral occu- 

 pying a vein nearly a foot in width, which has been called petalite. 

 But in hardness it corresponds more nearly with scapolite. It needs 

 farther and more accurate examination. At the same place, as well 

 as in the serpentine at Newbury, we find massive garnet. In Rus- 

 sell, in a supposed continuation of the Westfield serpentine, are found 

 veins of amianthus traversing the rock, which rock verges towards 

 a mineral that occurs in the Middlefield serpentine, as well as that of 

 Newbury, and has been denominated Deweylite, in honor of Prof. 

 Dewey. Chalcedony is also found in the Middlefield serpentine; 

 and it sometimes passes into hornstone. Large rolled masses of 

 these minerals, sometimes weighing 200 pounds or more, often aga- 

 tized, have been found in Middlefield and Chester, which probably 

 proceeded from some serpentine locality. Dr. Emmons says, that 

 steatite is crystalized distinctly in the serpentine at Middlefield ; and 

 he does not regard these crystals as pseudo-morphous ; although 

 mineralogists have generally considered the crystals of steatite as 

 such ; and Beudant makes a distinct variety of them under the name 

 of pseudomorphous steatite. The crystals at Middlefield certainly 

 correspond in form exactly to those of quartz. In the serpentine of 



