414 Pogue and Goldschmidt — Quartz from Alexander Co. 



Art. XXXYII. — On Quartz from Alexander County, North 

 Carolina;* by J. E. Pogue in Washington and V. Gold- 

 schmidt in Heidelberg. 



The complex development of quartz crystals from Alexan- 

 der County has been set forth in an important and thorough 

 contribution by G. vom Rath.f This occurrence, however, 

 shows such a wealth of forms that further investigation yields 

 many new ones. 



In the United States National Museum at Washington there 

 is a large number of crystals from this source, and the private 

 collection of V. Goldschmidt at Heidelberg also includes an 

 extensive series. Two crystals of peculiar interest, chosen 

 from the two collections, form the subject of this paper. 

 Their description may serve at the same time as an illustra- 

 tion of the methods employed in an investigation of this kind. 

 The measurements were made upon the two-circle goniometer 

 in Heidelberg. 



Crystal 1. (U. S. National Museum. Cat. No. 82917.) 

 Dimensions : 9x15""". Right-handed. Figs, la, lb, lc, show 

 the crystal from three sides in natural development. The dis- 

 tribution of the faces is represented in the gnomonic projec- 

 tion (fig. 3). The forms identified appear in the following 

 table : 



* 



Letter h r p * h k g 8 f d 



Symb. Gt. />£.- a> +10 —10 — -jj-0 +20 —20 +30 —30 +40 —60 



— Bravais. 1010 1011 1011 9097 2021 2021 3031 3031 4041 6061 



* * 



Letter s 1/ / r. f. f 0J 



Symb. Gt.pq.. 1 +1| +lf -fl — fl -21 — -Jl 



— Bravais . 1121 3253 l'Q-13'1 4373 3252 2131 7'3-10'3 



Of these forms those marked with an asterisk are new for 

 quartz. 



<f> = — -|0 (9097) is represented by three good faces. Meas- 

 ured and calculated values are in close agreement. 



Measured <£p = 0°05' ; 58°37' Calculated <j> P — 0°00' ; 58°3l' 

 0°10' ; 58°28' 

 0°01' ; 58°35' 



The form may be accepted as certain. 



* Published by permission of tbe Secretary of the Smithsonian Institution. 



fZeitachr. Kryst. vol. x, pp. 156-173, 1885. See also Hidden & Wash- 

 ington, this Journal, vol. xxxiii, p. 507, 1887, and Miers, ibid., vol. xlvi, pp. 

 420-424, 1893. Etch-figures on quartz from this locality have been described 

 by Molengraaff, Zeitschr. Kryst. vol. xvii, pp. 167-176, 1890. 



