378 



Decomposition of Iron Pyrites. 

 Density of Pyrite. 



Locality. 



Analyst. 



Sp. Gr 



Kind of Material. 



Freiberg, 



Breithaupt. 34 



5.001 





" 



' ' 



5.007 





" 



Mohs. 



5.031 





Rio Marina, Elba. 



C. Rammelsberg. 2 7 ; 5.027 



Pentagonal dodecahedra. 



" 



Kenngott and V. v. 4.976 



Smooth and shining crystals, 





Zepharovich. 28 



with minute black particles 

 of included hematite. 



" 



4.984 



A similar crystal. 



Elba or Piedmont. 



1 5.012 



A crystal with pure exterior, 

 but not free from included 

 foreign particles. 





r 



5.000 

 5.002 



■• 







5.017 

 5.018 





Piedmont, Elba, etc. 



" 



5.019 

 5.020 

 5.023 

 5.024 

 5.026 



Selected crystals, simple 

 [ and modified cubes. 





-. 



5.028 



. 



Traversella, Pied- 



Breithaupt. 34 



5.078 



Cube. 



mont. 



" 



5.097 





Piedmont ? 



I c 



Kenngott and V. v. 

 Zepharovich. 2 8 



5.112 



5.027 

 5.185 



Crystal. 



Traversella, Pied- 



C. Rammelsberg. 2 7 



4.967 



Octahedra. 



mont. 









d (i 



Kenngott and V. v. 



5.016 



A crystal having little lustre, 





Zepharovich. 33 





witli little cavities over its 

 surface occupied by brown 

 iron-ochre. 



Brosso, Piedmont. 



<< 31 



5.011 



A crystal with smooth and 

 brilliant surfaces, . slightly 

 striated. 



27 Zeits. d. geol. Ges. (1864), XVI, 268. 



28 Kenngott's Min. Notiz. (1855), No. 11. 



29 Sitzb. K. Ak. Wiss. in Wien (1853), XI, 392, (Kenngott's Min. Notiz. 

 No. 5). 



31 Kenngott's Min. Notiz. (1855), No. 11. 



32 Zeitschr. d. geol Ges. (1864), XVI, 267. 



33 Kenngott's Min. Notiz. (1855), No. 11. ■ 

 3 ^ Erd. Jour. f. pr, Chem. (1835), IV, 257. 



