ELISHA MITCHELL SCIENTIFIC SOCIETY. 



57 



privileged to discover in 1880, in Alexander connty, at the then 

 Milholland's iMill locality* proved to be the most perfectly devel- 

 oped crystals found up to that time, and in the hands of Dr. 

 Edward S. Danaf have given the first wholly reliable results ob- 

 tained for the species as to its angles. He found their axial 

 ratio to be c (vert.) : b : a = 0.95484 : 1.03163 : 1 ; with a (100) 

 over c(001)=-76° 20^ 



S a 



MONAZITE, PRISMATIC AND TWINNED, FROM ALEXANDER COUNTY. 



They were highly modified, very brilliant in lustre, of a light 

 t()[)az-yellow color and of perfect transparency. Many hundred 

 were found, but mostly of minute sizes; those of one-eighth 

 inc^h diameter were very rare. Nine different forms were iden- 

 tified and twelve in all were observed. The prismatic angle, I 

 over I (110 X HO), was determined very exactly, i. e., 93° 25f^ 

 For the first time the true form of this species was removed 

 from all doubt. 



The monazite of the Pilot Mountain gold region (Burke county) 

 has l)een carefully analyzed by S. A. Penfield,J of Yale College. 

 He states that ^'almost half of the bulk of this sand (after care- 

 ful concentration) is composed of resinous-looking grains of 

 monazite, from ^^gth to \\\\ inch in diameter, some showing 

 crystalline planes." By careful selection a sufficient quantity of 

 the pure monazite, of an even shade of color, for a complete 

 analysis in triplicate was finally separated. The specific gravity 



*Am. Jour. Sci., July, 1881, p. 21. 



fib., October, 1882, p. 247; lb., pp. 250—252. 



lib., October, 1882, pp. 247—254, E. S. Dana and S. L. Penfield. "Zeitsehrift fur Krys- 

 tallographie, etc.," 7, 363—365, Dana. 



