272 Mineral Resembling Meerschaum 



and that afterwards the crystals of iron oxide and hampshirite 

 developed from elements distributed through the soft mass. 



The same theory could be applied to the formation of the 

 associated minerals I have described. Iron and chromium, in 

 various combinations, are distributed through the magnesian 

 rocks of the region. Disintegrating and decomposing agen- 

 cies, constantly operating, cause the elements to mingle and 

 develop new combinations. 



The locality of these minerals is exactly on the line of 

 Middlefield, Hampshire county, and Chester, Hampden 

 county, beside the highway near where it crosses the Boston 

 and Albany railroad. From this justaposition the name 

 hampdenite seems appropriate to the pseudo-meerschaum 

 which I have described as the matrix of hampshirite and mag- 

 netite, and the name hampshirite, the same as has been used 

 by Emmons, Dewey and Herman, to the orthorhombic crys- 

 tals described and figured in this paper, imbedded with large 

 crystals of magnetite in the mineral, pseudo-meerschaum, 

 herein named hampdenite. 



The specimens of hampshirite have been examined by Mr. 

 A. L. Parsons, instructor of mineralogy in the University of 

 Minnesota, and their crystallographic characters are reported 

 in paragraph H below. 



H.— MORPHOLOGICAL, by A. L. Parsons. 



The material is well adapted for securing measurements, 

 though most of the faces are curved and pitted, particularly 

 the pyramidal. It seems likely that the pseudomorph was 

 formed by the loss of a part of the original material and hydra- 

 tion of that remaining. A list of the probable minerals from 

 which it could be derived comprises enstatite, olivine, and the 

 humite group. 



Enstatite is dropped from consideration on account of the 

 non-correspondence of angles. In the case of olivine, it is 

 possible to get forms corresponding to the prismatic faces but 

 the pyramidal faces would not correspond. The humite group 

 exhibits a remarkable similarity of habit and its ordinary asso- 

 ciation with other minerals is so similar that there seems but 

 little reason to doubt the original mineral was humite or pos- 

 sibly chondrodite. Aside from crystallographic grounds thcrr 



