No. 75.] 



127 



EARTHY MINERALS. 

 SILICA. 



QUARTZ. 



(Mineralogy of New- York, page 257.) 



To the full account which is contained in the Mineralogy of New- 

 York, of our remarkable localities of quartz, I have still to make several 

 additions. Herkimer county has furnished such an almost countless 

 number of specimens, which have been distributed among the various 

 cabinets, that it is by no means strange that new and interesting crys- 

 talline forms are from time to time discovered. The figure annexed is 



from Middleville, and is copied from Mr. Alger's edition of Phillips' 

 Mineralogy, (page 6.) It is similar to the fig. 133, in the Mineralogy 

 of New-York, which is from a crystal found in Greene county. 



Subsequent examination of the crystalline forms from this county, 

 has led me to doubt whether fig. 152, of the Mineralogy of New-York, 

 and fig. 9 a, (page 409) of Dana's Mineralogy, 2d edition, are really 

 true modifications of this mineral. The first was copied from Shepard's 



Mineralogy. The faces o and a, as represented in these figures, seem 

 to be accidental, and to have been formed by the pressure of some por- 



