384 Genth and Penjield — Contributions to Mineralogy. 



3. Lollingite. 



The arsenide of iron from Halyburton's and Drum's farms 

 which, from qualitative tests, had been mentioned in my 

 Minerals of North Carolina,* as leucopyrite, was found to be 

 lollingite. 



A specimen from Drum's farm, Alexander County, mostly 

 oxydized into scorodite, etc., yielded some very pure frag- 

 ments of from 4 to 6 mm in size. They did not show any crys- 

 talline faces, apparently amorphous ; fracture conchoidal. -Sp. 

 gr. 7 "031. The analysis gave : 



Fe 70-83 



Cu . trace 



As _. 27-93 



S 0-77 



99-52 



4. Untile. 



The flesh-colored orthoclase from West Cheyenne Canon, 

 El Paso Co., Colorado, contains minute black crystals which 

 were identified by Professor Penfield as rutile. 



Prom the specimens received by Messrs. Geo. L. English & 

 Co. it appears that these crystals are rarely in contact with the 

 orthoclase, but generally implanted in the more recent quartz, 

 resulting from its alteration and filling its cavities. 



The rutile crystals are from 05 to 4 mm in size. 



The forms which have been observed on them are «, 100, i-i ; 

 on, 110, I ; I, 130, i-S ; e, 101, 1-i and s, 111, 1. Some of the 

 crystals are like fig. 1, a habit which is not common with 



rutile but reminds one rather of cassiterite. Many of the crys- 

 tals have four of the pyramid faces, s, larger than the others 

 and developed apparently into monoclinic prisms. Fig. 2 rep- 

 resents one of the distorted crystals in ordinary projection and 

 fig. 3 is a basal projection' of another, with a still more pro- 



* The Minerals of North Carolina, by Frederick Augustus Genth, Bulletin No. 

 74, U. S. Geol. Survey, Washington, 1891. 



