Jamesonite Group, from Two Localities. 



67 



name. The name mullanite is after Capt. John Mullan, 

 who in 1858 began construction on the military road con- 

 necting Fort Benton, Montana, with Fort Walla Walla, 

 Wash. The Mullan Eoad furnished a means of access 

 to the Coeur d'Alene region and resulted in the dis- 

 covery of the important mineral deposits of the district. 

 Both of the mines in which the new mineral has been 



Fig. 1. 



Fig. 2. 



rn 



a 



m 



71 



found are located near this old highway. Incidentally 

 the name indicates one of the localities, Mullan, Idaho, 

 also named after Capt. Mullan. 



Occurrence. — The mode of occurrence of mullanite in 

 the Iron Mountain Mine is the same as that described 

 for epiboulangerite. No distinction was made between 

 the two minerals in the field. The gray sulphantimonite 

 occurs in grains and minute needles throughout the vein 

 material and the granular sphalerite of the ore, constitut- 

 ing about 15% of the zinc ore as shipped. It also occurs 

 as bunches and masses of fibers in snowy white quartz 



