268" New Specific Gravities of Minerals. 



Art. IX. — Breithaupfs new Specijic Gravities of Minerals ; by 

 Dr. Lewis Feuchtwangeb, of New York. 



The indefatigable Prof. Breithaupt, of Freiberg, in whom mine- 

 ralogy has its most zealous cultivator, and to whom the scientific 

 world owes great discoveries for the last fifteen years, has lately re- 

 examined a great number of minerals the specific gravity of which 

 has in many instances not yet been known at all, and in some instan- 

 ces could not from circumstances be given correctly, and they are: 



1. 2.629, Common siliceous schist, lydian stone from Erzge- 



birge. Saxony. 



2. 2.761, Bitterspar, from Iringen. 



3. 2.717, Eugnostic calcareous spar, from Rotluf near Chem- 



nitz, Saxony. 

 A AiQ'i ) ^''O'^ o''^5 Ilmenite, from the Uralian mountains, ac- 

 _* ^'^qV { coaipanying the zircon in granite, black and con- 

 ' ) choidal. 



6. 2.330, Comptonite, from Vesuvius. 



7. 2.361, The same, from Bohemia. 



8. 3.002, Small and fine granular batrachite from Tyrol. 



9. 22.109, INative iridium in grains, lately received from Uralian 



Mountains. 



10. 17.840, Two pretty large and pure grains of iridosmin, from 



Uralian Mountains. 



11. 3.185, Fluorspar-crystal, from Switzerland. 



12. 1.989, Brown sulphur, from Croatia. 



1 3. 2.724, Scapolite, from Arendal, Norway, fresh greenish grey 



and hardness 7. 



14. 2.241 , ) Opal, Werner's semi-opal from Freiberg, the hardest 



15. 2.250, y known varieties. 



1 7* '^ fi9f\ i Stilpnosiderite, from the Voigtland. 



18- 2.700, Meroxenecalcareousspar, (spar R. = 105^ 11',) from 

 Tharaud, Saxony. 



19. 7.198, Calamine leadspar, (white phosphate of lead,) from 



Zschoppau, Saxony. 



20. 3.388, Transparent crystal of epidote, from Piedmont. 



21. 3.351, Pyroxene, which deserves more investigation, passing 



generally for acolophonite from Arendal, Norway. 



22. 3.437, Retinophane pyroxene, the common colophonite, 



from Arendal. 



