EMERY MINE OF CHESTER, 



HAMPDEN COUNTY, MASS., 

 WITH REMARKS ON THE NATURE OF EMERY AND ITS ASSOCIATE MINERALS. 



Considerable interest is attached to the recent developments 

 of an extensive deposit of emery in Chester, Hampden County, 

 Mass., by Prof. C. T. Jackson ; and my name has been asso- 

 ciated in various ways with it, without my having had any 

 thing directly to do with it. Sundry communications have 

 also been received by me from various parties These com- 

 munications are best answered by the facts embraced in this 

 article, some portion of which it has always been my intention 

 to publish, without reference to the special interest of any one 

 in the matter. 



Prior to 1846 emery was simply known as a mineral, coming 

 to us from a few remote localities, and was used in the arts 

 without our having any knowledge of its true geological posi- 

 tion or its mineralogical relations. About that period circum- 

 stances favored my commencing those geological and mineral- 

 ogical discoveries in relation to emery that were afterward 

 embodied in two papers presented to the Academy of Sciences' 

 of Paris in 1850, in which the subject was thoroughly discussed, 

 and I might say almost exhausted. The light in which those 

 discoveries were considered will be seen by the conclusions 

 of the report of the committee of the Academy, consisting of 

 Messrs. Dufrenoy, Elie de Beaumont, and Cordier, viz. : 



" It results from the review just given of the labors of Dr. 

 Smith, that he has made known — 1. The precise nature of the 

 geology of emery in Asia Minor and the Grecian Archipelago. 

 2. That he has described the properties of the principal min- 

 erals associated with it, and the manner in which they occur, 

 especially diaspot*e and emerylite ; this last mineral forms, by 

 the identity of its composition in the different formations that 



