36 ECONOMICAL MINERALOGY. 



In the Counties of Madison, Onondaga, and in some of the still more western ones, there 

 not unfrequently occur deposits, to which Mr. Vanuxem has given the name of Tufaceous 

 Iron Ore, being a mixture of calcareous tufa and hydrate of iron. Among other localities, 

 may be noticed one a mile west of Chittenango in Madison county ; another, two and a half 

 miles northeast of Salina in Onondaga ; and another on Nine-mile creek, between Marcellus 

 and the great embankment of the SjTacuse and Auburn railroad. 



The proportion of oxide of iron in tliis compound is usually small. With the magnetic 

 oxide, it would be valuable as a flux ; but it so happens that the abundant iron ore of Western 

 New-York, (the lenticular clay iron ore,) is itself largely mixed with carbonate of lime. 



