Moses — Mineralogical Notes. 



103 



mp 



(4) Realgar Crystals from Snohomish County, Washington. 



The described occurrences of realgar in this country have, I 

 believe, none of them yielded measurable crystals.* Certainly 

 this is the case with the stalagmitic material from Yellowstone 

 Park -described by Weed and Pirssonf and the bladed, con- 

 fusedly aggregated crystals found by Blakef beneath the lava 

 in Iron County, Utah. 



Through the kindness of Prof. J. F. Kemp I received a 

 specimen of crystallized realgar from a vein two to four inches 

 A thick in a tunnel of the Penn Mining Co., 



Monte Cristo Mining District, Snohomish 

 County, Washington. The crystals rest upon 

 a thin layer of nearly black tarnished mar- 

 casite. 



Most of the crystals are long, prismatic, 

 and so embedded that little more can be seen 

 than the deeply striated faces of the prism 

 zone, sometimes 30 mm in length. Some small- 

 er crystals, however, show also three terminal 

 planes suggesting a flat rhombohedron. 

 The best of these crystals, approximately 2 X2 nim cross sec- 

 tion, was carefully detached and measured with the two-circle 

 goniometer. The occurring forms were, as shown in fig. 4 : 



Pinacoids. — a (100) and b (010) small but yielding fair sig- 

 nals, c (001) large but dull. 



Prisms. — The prism faces were striated, but two faces of 

 in (110) yielded faint separate signals, three faces of I (210) 

 yielded moderatelv good signals, and there were indications of 

 faces of h (670). 



Pyramids. — The faces of n (212) yielded good reflections. 

 The coordinate angles measured and calculated were: 





Measured. 







Calculated. 



Face. 







P 











P 



c (001) 



89°32' 



23 c 



51' 



90° 





23°55' 



b (010) 







90 











90 



a (L00) 



90 01 



90 





90 





90 



1(210) 



56 18 



90 





56 



38' 



90 



m (110) 



37 11 



90 





37 



13 



90 



n (212) 



31 33 



29 



36 



31 



16 



29 38 



VrbaJ figures a crystal from Bosnia with the same predomi- 

 nating forms. 



*This Journ., xlii, 403, 1891. f This Journ., xxi, 219, 1881, and letter. 



\ Zeitschr. f. Kryst., xv, 46, fig. 10. 



