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NEW YORK STATE MUSEUM 



syenite. The former stone is quite like that quarried at Keese- 

 ville and called erroneously " Keeseville granite the rock being 

 a gabbro and very similar to the Hand hill rock. It is a very 

 handsome, strong stone, takes a beautiful polish and would seem 

 to be well adapted for structural and ornamental purposes. It 

 would certainly seem as good as the Keeseville rock but has not 

 been sufficiently investigated to enable any precise statements 

 of its value to be made. The numerous diabase dikes are some- 

 thing of an impediment to quarrying operations, specially as the 

 adjacent gabbro is apt to be excessively jointed and useless. 



The augite-syenite furnishes a greenish black, fine grained rock 

 which is also strong and takes a fine polish. The change in color 

 which this rock experiences on exposure may prove harmful. 

 This change takes place rather rapidly, though it varies in differ- 

 ent parts of the rock and may be a matter of a considerable num- 

 ber of years in this case. There is however but little of this rock 

 on the hill, as has been previously noted. It should also make 

 a good paving stone, as well as a valuable road metal. For this 

 latter purpose the gabbro will also serve excellently, and much 

 of the Dannemora gneiss as well, though in using the latter care 

 mnst be taken not to use material of varying hardness on the 

 same piece of road. 



