GEOLOGICAL AND MINERALOGICAL NOTES, 



NO. 9. 



BY JOHN H. SEARS, 



Curator of Mineralogy and Geoloyy, Peabody Academy of Science, 

 Salem, Massachusetts. 



LIST OF THE MINERALS OF ESSEX COUNTY, MASSACHUSETTS. 



The following list of the minerals of Essex County has 

 been prepared after a careful examination of the work of 

 the earlier mineralogists and dilligent search in almost 

 every portion of the county for species not previously 

 noticed. With so few persons devoting themselyes to the 

 study of mineralogy or collecting specimens in this region, 

 it is not possible to present an absolutely coniplete list. 

 Of the minerals here enumerated nearly all are represented 

 by excellent specimens in the County collection in the mu- 

 seum of the Peabody Academy of Science in Salem. 



As early as 1821, Prof. J. W. Webster discovered the 

 minerals epidote and fibrous prenhite at Nahant and made 

 analyses of theni (American Journal of Science, Vol. in, 

 page 364), and in 1823 he discovered the green feldspar 

 and zircon crystals at the hill on the south side of the 

 common in Beverly. In theanalysis of the green feldspar 

 he mentions the metallic particles in the Compound, which, 

 he writes, are probably oxide of titanium (Boston Jour- 

 nal of Philosophy, Vol. i, pp. 390-599). In the Amer- 

 ican Journal of Science (Vol. xxxiv, p. 402, 1838), is 



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