NOTES ON METALLIC MINERALS— SHANNON. 593 



A paper by Guillemain ^ gives analyses of material from Ober- 

 Lahr, St. Antonio, and Betzdorf agreeing almost exactly with the 

 formula SPhS-SbaSg. These results differ so sharply from those 

 of other analysts on materials from the same localities that they 

 have not been further considered here. The paper contains no 

 reference to the results of Sjogren, published the preceding year. 



IDENTITY OF MULLANITE WITH BOULANGERITE. 



From the preceding discussion it is clear that the true formula 

 for boulangerite is the same as that originally assigned to mullanite, 

 which, therefore, is chemically identical with boulangerite. The 

 angles measured on the imperfect crystals did not agree with those 

 of diaphorite, as stated in the original paper, but it is not impossible 

 that by adopting a different orientation the observed forms could be 

 referred to the axial values given for boulangerite by Sjogren. Un- 

 fortunately the original measurements were not published and the 

 notes are not now available. There exists no sufficient ground for 

 separating the materials called mullanite from typical boulangerite. 

 The first two boulangerites described below are the original occur- 

 rences of " mullanite." 



BOULANGERITE FROM THE GOLD HUNTER MINE, MULLAN, IDAHO. 



In the lead silver ore of the Gold Hunter mine at Mullan, in the 

 Coeur d'Alene district, Idaho, boulangerite is a constant constituent 

 of the more quartzose portions of the ore occurring commonly as 

 small fibrous masses in quartz or as thin acicular needles in small 

 cavities in quartz which are lined with crystals of quartz or siderite. 

 In color the mineral is steel-gray, with a brownish gray to brown 

 streak. The specific gravity of the needles was determined to be 

 6.407. Excellent specimens are frequently obtained at the mine. 

 Some typical specimens showing abundant needles lining cavities 

 in quartz have recently been received at the United States National 

 Museum from Mr. C. L. Herrick, manager of the mine (Cat. 93760). 

 Upon analysis the needles of boulangerite from this locality yielded 

 the results given below, the iron being due to siderite present as 

 impurity in the sample : 



Analysis of boulangei~ite from Mtillan, Idaho. 



Lead 53. 33 



Antimony 24. 67 



Sulphur 18. 11 



Arsenic , 64 



Iron 1_ 47 



Total 98. 22 



1 Guillemain, C, ZeitschrWt Kryst. Min., vol. 33, p. 74, 1900. 

 181404— 21— Proc.N.M.vol.58 38 



