JAN. 19, 1921 PARDEE, LARSEN, & STEIGER: BEMENTITE 



29 



TABLE 1. Analyses of Bementite, Caryopilite, and Inesite. 



SiO...... 



MnO... 

 FeO.... 



MgO.. . 

 CaO.... 



ZnO.... 



PbO.... 



Alkalies . 



AlsO.i... 



Fe203... 



mo--. . 

 H20+.. 

 ci 



Si02.. 

 MnO. 

 FeO.. 

 MgO. 

 CaO.. 

 ZnO.. 

 PbO.. 

 AI0O3. 

 FeoOs. 

 HoO.. 



Si02... 

 MnO''. 

 H2O... 

 AI2O3.. 



100.22 



99.70 



100.00 



99.85 



100.72 



TABLE 2. Molecular Ratios. 



99.29 



100.00 100.00 100.00 100.00 100.00 100.00 

 ''Under MnO have been summed up the molecular ratios of MnO, FeO, IMgO, CaO, 

 ZnO, and PbO. 



The average molecular ratio of the three analyses of bementite is 

 4O.7Mn0.24.iH20.34.8Si02, and agrees very nearly in composition 

 with the formula SMnO.sHsO.ySiOo. 



Written in the rational form this formula becomes SMn.io H.ySi. 

 27O or 5MnH2Si04.MnoSi04.MnSiO3. 



Leaving out water leads to the rather more simple rational formula 

 8Mn.7Si.22O.5H2O, or 6MnSiO3.Mn2SiO4.5HoO. 



Identity of bementite and caryopilite. 

 The distinction between bementite and caryopilite has been based 



