ELISHA MITCHELL SCIENTIFIC SOCIETY. 71 



III Plate 3 the figures 1, 2, 3, 4, 5, 8 and 9 are of crystals 

 <lisc()vered, by the writer, during the progress of the work at 

 the emerald and hiddenite mine, and now constitute a part of 

 the unique ''suite" of North Carolina minerals owned by Mr. 

 C. S. Beinent, of Philadelphia. 



ProfessiU" Vom Rath states that "Dearly all the known forms 

 of quartz seem to have been discovered in a small area of Alex- 

 ander county, and much to his surprise he observed several 

 planes {ticehe in all) new to science." Certainly these quartz 

 crystals far surpass, in their various points of scientific interest, 

 all the discoveries in this species made elsewhere in this country 

 within the past ten years. 



Since 1879 the writer has been much interested in the so- 

 called "basal-planes" on quartz crystals from North Carolina. 

 My experience goes to prove that genuine basal planes are of 

 very rare occurrence in this species. In the great majority (jf 

 cases the planes observed have been produced by compression or 

 juxtaposition. From among many crystals, appearing, when 

 superficially examined, to possess this rare plane, I have selected 

 only two which have a natural and normal development of the 

 basal pinacoid. Upon being carefully measured with a reflective 

 goniometer (by Alfred Des Cloizeaux, at Paris, May 8th, 1886) 

 the angle -{- R over O = 128°, whereas the calculated angle is 

 128° 13^ Therefore the occurrence of this face is removed from 

 all manner of doubt, as Des Cloizeaux has already stated. This 

 plane seems often attempted to be formed, but the result is hum- 

 mocky and uneven. A rough unpolished basal truncation is 

 common on the Alexander and Burke county quartz crystals, 

 but a smooth basal plane is a rarity. 



Figure 7, Plate 3, exhibits a basal plane crystal (otherwise 

 rarely modified) discovered by Mr. J. A. D. Stephenson in Ire- 

 dell county, and is part of a remarkable "suite" collected and 

 owned by him. 



The quartz crystals from some of the localities in Western 

 North Carolina have attained a wide celebrity from other reasons 

 than their interesting outward form or their clearness; the inclu- 



