56 Geology add Mineralogy of a part of Massachusetis, dé. 
Ochry brown. The formation of the cylindrical and sta- 
lactical hematite seems to be involved in perfect darkness. 
They are sometimes equally solid throughout, and the 
fibres radiate from the axis; at other times, they contain a 
less perfectly crystallized cylinder along the axis; and in 
other specimens, the central cylinder is mere yellow oxide 
of iron, upon which -the process of crystallization has not 
even commenced. Some of the cylinders, formed of ra- 
diating fibres as before, are hollow, or may be easily made 
so. ‘They are often formed on the inside of hollow sphe- 
roidal masses of the ore, and their terminations are always 
downwards. But it is not easily conceived how the action 
of fire should melt and thus crystallize the ore on the in- 
side, while the outside of these metallic geodes, often not 
half an inch thick, is entirely without any appearance of 
fusion or tendency towards crystallization: neither how the 
action of either fire or water should form the cylinders 
with the central part such as it often presents. ‘The smooth 
surfaces of the ore are often beautifully crised. 
fron ore is also found at Middlefield, but not of a quality 
for manufacture. Emmons. 
' 5. ARGILLACEOUS OXIDE OF IRON. 
The granular and compact varieties are found in Ben- 
nington and Salisbury. 
Bog iron ore is found occasionally in the low grounds. - 
In Sheffield, in some quantity. 
6. SULPHATE OF IRON, 
Effioresces on the rocks near the S. village in Adams. 
Also ina loose earth, near the Shaker village in Tyringham. 
7. CHROMATE OF IRON. 
In Cummington with steatite. Porter. It mueh re- 
sembles that from Maryland. 
