590 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



ily available by Hintze,^ this compound was described as a distinct 

 species and given the name miillanite.^ Some imperfect crystals 

 gave angles which seemed unlike those of diaphorite, but they were 

 too poor in quality to serve alone as a basis for considering the 

 material distinct from that of Sjogren. Since mullanite evidently had 

 no reasonable claim to distinction and should be eliminated from 

 the literature, it was planned to immediately publish a retraction. 

 Before doing so, however, several new analyses of boulangerites 

 from various localities were made, and the early literature relating 

 to this species was examined critically. Below is given a summary 

 of the literature and descriptions and analyses of boulangerites from 

 several new localities. 



EAKLY DESCRIPTIONS OK BotTLAXOEUITB. 



Boulanger^ in 1835 published an analysis of a "double sulphide 

 of antimony and lead " from Molieres, Department du Gard, France. 

 The material was in crystalline-fibrous bluish-gray metallic masses, 

 having a specific gravity of 5.97. The mineral was associated with 

 pyrite in quartz and was in part altered to antimony and lead oxides 

 and limonite. Boulanger's original analysis is given in the following 

 table, column 1. In column 2 is given the analysis recalculated after 

 deducting impurities, and in column 3 are given the ratios derived 

 from the figures of column 2. 



Analysis and ratios of houlaiKjcriic from Molieres, France. 



'•Ori^-'-'cuK-l 



Lead 



Iron , 



Copper . . . . 

 Antimony. . 

 Sulphur . . . 



Pyrite 



Quartz 



Total 



49.00 



1.10 



.80 



23.20 



16.90 



5.60 



.60 



97.20 



53.90 



1.20 



.90 



25.50 



18.50 



0. 2603 

 .0215 

 .0141 

 .2122 

 .5769 



100. 00 



29.59 



21.22 

 57.69 



5.57X1.00 



4.00X1.00 

 10.90X1.00 



The ratios thus give 5.57PbS.2Sb2S3, or midway between the two 

 formulas, 3PbS.Sb,S., and 5PbS.2Sb5S,. Critical examination of the 

 analysis, however, shows defects which tend to make the ratios un- 

 reliable. In the first place, the analysis as given shows a deficiency 

 of 2.8 per cent, a part of which is evidently sulphur. Copper and 

 iron are not commonly constitutional constituents of boulangerite, 

 particularly copper. If we assume these two bases to be extraneous 



J Hintze, Carl, Handbuch der Mlneralogie, vol. 1, p. 1040, 1904. 

 'Shannon, E. V., Amer. Journ. Sci., vol. 44, p. 66, 1918. 

 • Boulanger, C, Annales des Mines, vol. 7, p. 575, 1835. 



