JEL. L. Wells — Bismutosphcerite from Connecticut. 271 



Art. XXX. — Bismutosphcerite from Willimantic and Portland, 

 Conn.; by H. L. Wells. 



Through the kindness of Professor Brush I have been en- 

 abled to examine two specimens of basic bismuth carbonate 

 which are of considerable interest, inasmuch as their composi- 

 tion appears to be identical with that of Weisbach's bismuto- 

 sphserite.* Weisbach gave this name, upon reinvestigation, to 

 Werner's "Arsenik-Wismuth," which, as he remarks, had been 

 called "Luftsaures Wismuth" by Adolph Beyer, who died as 

 early as 1805. The composition of bismutosphserite has been 

 considered doubtfulf because Winkler's analysis included no 

 water and footed up only to 97*83 per cent, but Weisbach states 

 distinctly that the mineral is anhydrous, and, since Winkler 

 used only 330 milligrams of the material for his analysis, it is 

 quite probable that his loss may have been due to other causes 

 than the presence of water. 



The specimen from Willimantic, which weighed about \ lb., 

 was given to Professor Brush by H. N. Bill, Esq., of Williman- 

 tic, who has kindly furnished the following description of the 

 locality. "The mineral occurs in small isolated masses embed- 

 ded in albite with garnets. The vein of which it was a part 

 was composed of large crystals of orthoclase, muscovite and oc- 

 casional fine crystals of smoky quartz. The locality is on the 

 Linen Co's property near the west end of mill JSTo. 2. A consid- 

 erable outcrop of gneiss originally existed at this point, but it 

 has all been utilized in building the mill. It was during the 

 blasting of this ledge that the vein was opened and the mineral 

 discovered. The locality is now inaccessible, the blasted por- 

 tion being covered by a fine grassy lawn, while the portion orig- 

 inally exposed in the bed of the river has been flooded by a 

 pond." 



The material of which the specimen is almost wholly com- 

 posed has a dark gray color and gives a light gray streak. It 

 shows evidences of a bent columnar structure, suggesting that 

 it is a decomposition product of bismuthinite, and a small nu- 

 cleus of bismuthinite, found in the interior of the specimen by 

 Professor Brush, shows that this is the actual source of the min- 

 eral.^: Its hardness is between that of calcite and that of fluorite 

 (3'5). The specific gravity is 742 according to a determination 

 made on a chemical balance with the precaution of removing 

 air from the fragment used by placing it in boiling water before 



* Jahrb. Berg-Hutten., 1877, p. 49. — Dana's Mineralogy, 5th edition, Appendix 

 III, p. 15. 



f A. H. Chester, this Journal, HI, xxxiii, p. 291. 



% "Weisbach states (1. c.) that the original bismutosphserite often encloses a nu- 

 cleus of metallic bismuth. 



