GEOLOGY AND MINERALOGY OF NEWBURY. 167 



judge that the whole amount was not large. "Why the 

 quarry was abandoned I have not been able to learn. 



It is in the " Devil's Den" that the most interesting 

 minerals in Newbury are found. I have visited it and the 

 other localities here for the last twelve years. First in in- 

 terest is the serpentine, varying from a rich bottle green to 

 a leek green ; the first compact, pure and translucent, the 

 second impure and opaque ; the most harmful impurity 

 being iron pyrite disseminated through the mass. 



Great expectations were once entertained as to the 

 commercial value of this rock, and a company operated 

 the quarry for marble, but nothing has been done in a 

 commercial way for many years. A shaft was sunk in the 

 field, not far off, during the silver excitement, but was 

 soon abandoned. Quantities of a beautiful porphyritic 

 rock were thrown out, that in masses, might prove to be 

 profitable. 



At present, hardly enough attractive rock is in sight to 

 warrant great expectations, and the large masses of wol- 

 lastonite, garnet, calcite and dolomite mixed with the ser- 

 pentinic limestone would seem to confirm this view ; but 

 when we consider that the excavations have not even re- 

 duced the knolls to the level of the surrounding country, 

 and the " Den" itself is a very modest pit, the resources 

 of the place can hardly be said to be exhausted. 



I am firmly of the belief that some generous blasting 

 would reveal an abundance of tine, rich stone, superior to 

 any verde antique marble in our market. Associated 

 with the serpentine are masses of wollastonite, once 

 called tremolite. It is a beautiful white mineral, in long, 

 bladed, radiated crystals. It is too brittle to serve any 

 other than the mineralogist's purpose. 



Masses of compact garnet are also found at the " Den.' 

 When associated with or disseminated through the ser- 



