1912] Eakle: The Minerals of Tonopah, Nevada 



19 



orthopinacoid and some of them are exceedingly thin and almost 

 transparent, with a deep red color. They are vertically fur- 

 rowed and striated and the least touch breaks them into slender 

 rods by the easy clinopinacoidal cleavage. Many of the broad 

 plates have frayed-out ends, while others are terminated by dull 

 bases. The predominating habit shows a broad, striated, front- 

 pinacoid grading into prisms and terminated by a rough base 

 and two small faces of the rear pyramid (111), as seen in 

 figure 9. Some of the stouter crystals gave very good readings 

 with the two-circle goniometer, since the striations did not pre- 

 vent good polar orientation. The prismatic zone was a multiple 

 of narrow striated faces and gave a train of wedges from which 

 only a few could be distinguished as definite forms. Since the 

 crystals are very thin, the pyramidal faces were all small, but 

 mostly very bright. One new pyramid (122) occurred on some 

 of the crystals, in good reflecting faces. The forms observed 

 on the crystals and the angles measured and calculated are as 

 follows : 





c (001) 

 b (010) 

 a (100) 

 r (120) 





m (110) 

 q (830) 

 h (310) 

 s (121) 





d (211) 

 o (Til) 

 e (112) 

 V (122) new- 











Measured 



Calculated 



m 



CO 



110 



e 



49°48' 



P 



90°00' 



e 



50°27' 



P 



90°00' 



3 



foe 



830 



72 54 



90 00 



72 48 



90 00 



h 



3co 



310 



74 40 



90 00 



74 37 



90 00 



r 



a>2 



120 



31 00 



90 00 



31 12 



90 00 



s 



—12 



121 



30 34 



63 34 



51 00 



63 41 



d 



—21 



211 



67 05 



66 21 



67 29 



66 10 







— 11 



Til 



50 00 



54 00 



50 14 



53 42 



e 



-u 



112 



50 00 



34 19 



50 01 



33 59 



V 



— il 



T22 



30 50 



45 14 



30 48 



45 15 



Wulfenite. — Thin basal plates of wulfenite occur associated 

 with barite and crystals of iodyrite. Twinned crystals of 

 iodyrite have been deposited on the wulfenite plates and are 

 therefore of later generation. The plates are almost colorless and 



