1922] 



NATURAL SCIENCES OF PHILADELPHIA 



117 



Wavellite, Moore's Mill, Pennsylvania 



The wavellite from Moore's Mill, Cumberland County, Penn- 

 sylvania was described and figured by Ungemach. The locality is 

 an abandoned wavellite mine about a mile south of Moore's 

 Mill Station. 



Two crystals were measured by the writer. The results are 

 given in Table V. The following forms were noted: a (100), b 

 (010), c (001), m (110), w (650), R (970), 1 (430), i (320), N (210), 

 h (310), k (510), t (710), g (270), and o (121), of which c, w, R, 

 N, k, t, and g, are new. The habit of the crystals is like those 

 of Ungemach, and the new forms excepting g are line faces 

 occurring in the striations between a (100) and m (110) of his 

 figure; g is a line face between b (010) and m (110). 



Table V. Wavellite Forms, Moore 's Mill, Pennsylvania 



Let- 

 ter 



Form 



Miller Gds. 



Faces 

 meas- 

 ured 



Calculated 



9 P 



Measured 



9 P 



Signal 



New forms marked * 



Wavellite, Montgomery County, Arkansas 



Montgomery County, Arkansas, is the most famous of the 

 American localities for wavellite. It produced in abundance 

 beautiful green radiating aggregates of the mineral in fissures 

 in a sandstone. Frequently the radiations terminate in druses 

 of small crystals. 



A single crystal was examined, but gave very poor reflections. 

 The forms noted were b (010), m (110), and p (101); the latter 



