372 



C. H. Warren — Mineralogical Notes. 





Measured, 



Calculated. 



no /s no 



= 61° 



61° 13' 



no ^ 010 



= 58£ 



59 23£ 



001 xv no 



= 67 



67 47 



001 /v 201 



= 80 



80 18 



m ^ m 

 m /\ b 



c ^ m 

 c * y 



Sections parallel to both cleavages were prepared and showed 

 on £, 010, an extinction of +9° to 4-10°, and on c, 001, one 

 approximately parallel to the a axis. Under crossed nicols the 

 sections show a difference of shading or cloudiness, indicating 

 that the crystals are not of homogeneous structure. Kaolini- 

 zation has commenced to some extent and a small amount of a 



white lustrous mica can be seen. The large extinction-angle, 

 + 9° to +10° on 010, would seem to indicate a soda-orthoclase. 



Crystals of Iron Wolf ramite from South Dakota. 

 The Wolframite crystals were sent by Mr. W. M. Foote of 

 Philadelphia, Pa., but the exact locality from which they were 

 obtained could not be ascertained. The crystals, the largest of 

 which are about 4 mm long and not over l mm in thickness, are 

 found filling numerous small cavities in a highly siliceous rock. 

 They are elongated in the direction of the ortho-axis, and, as 

 the ortho-pinacoid and base are the most prominent forms, the 

 crystals present the appearance of a nearly rectangular prism. 



This prism is given a wedge-shaped 

 5 termination by the development of 



*< Z '. '. c ^j_lSp^\ the several prism faces, as can be 



seen from tig. 5. The majority 

 of the crystals show a decided vici- 

 nal development of their faces and 

 other irregularities. By using a 

 strong illumination and the 8 ocular 

 with a Fuess reflection goniometer satisfactory measurements 

 were obtained from one of the smaller and more perfect crys- 

 tals. The following forms were identified, of which the prism 

 i, 7'11'0, is new : 



r 



a 



100, 



c 



001, 



s 210, 



t 



102, 



f 011 



b 



010, 



m 



110, 



i 7-11-0, 



y 



102, 



A 112 



