Brownmillerite

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General Brownmillerite Information

Chemical Formula:  Ca2(Al,Fe+++)2O5  
Composition:  Molecular Weight = 240.09 gm  
   Calcium   33.39 %  Ca   46.71 % CaO  
   Aluminum  12.36 %  Al   23.36 % Al2O3  
   Iron      20.93 %  Fe   26.93 % FeO  
   Oxygen    33.32 %  O  
            ______        ______   
            100.00 %       97.00 % = TOTAL OXIDE  
Empirical Formula:  Ca2Al1.1Fe2+0.9O5  
Environment:  Thermally metamorphosed limestone blocks included in volcanic rocks.  
IMA Status:  Approved IMA 1964  
Locality:  Ettringer-Bellerberg volcano, near Mayen, Eifel district, Germany. Link to MinDat.org Location Data.  
Name Origin:  Named for Lorrin Thomas Brownmiller (1902-1988), Chief chemist of the Alpha Portland Cement Company, Easton, Pennsylvania, USA.  
Synonym:  ICSD 9197  
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