UNIVERSITY OF CALIFORNIA PUBLICATIONS 



BULLETIN OF THE DEPARTMENT OF 



GEOLOGY 



Vol. 6, No. 9, pp. 179-189, Pis. 30-31 June 28, 1911 



NEOCOLEMANITE, A VARIETY OF 

 COLEMANITE, AND HOWLITE FROM 

 LANG, LOS ANGELES COUNTY, 

 CALIFORNIA 



BY 



AETHUR S. EAKLE 



TABLE OF CONTENTS 



PAGE 



Neoeolemanite 180 



Occurrence 180 



Origin of the deposit 180 



Structure of the mineral 182 



Crystal habits 182 



Forms 183 



Measurements of the crystals 184 



Determination of the polar elements 185 



Axial ratio 186 



Optical orientation 186 



Indices of refraction 186 



Chemical composition 187 



Howlite 187 



Occurrence 187 



Origin of the mineral 188 



Chemical composition 188 



Associated calcite 189 



