4 CALIFORNIA ACADEMY OF SCIENCES. 



The material was free from cliromite.and nwarowite. 



To facilitate comparison, I give here one of the manjr 

 analyses of kiimmererite (from Dana's Mineralogy), and v. 

 Leuchtenberg's analysis of kotschubeite. 



kammererite. Uotschubfite. 



Texas, Pa. Ural. 



H2O ....13.20 % 12.63 % 



Si O2....3I.3I " 32.67'' 



CrsO .... 2.98 " 4.09" 



AJ2O3 ...12.8i '•' 13.18" 



FeO .... 2.46 " 2.22 (Fe. O3) 

 MO.... 0.45 " 

 Ca O . . . . 0.82 " 



MgO ....35.02" 35.65 % 



99.08 100.53 



The two forms of chlorite, penninite and dinochlore (I'ipi- 

 dolite in Dana's Mineralogy) have, according to Rammels- 

 berg, substantially the same composition, and differ only in 

 their crystallization, penninite being hexagonal, and dino- 

 chlore monoclinic. Both have varieties rich in chromium: 

 that corresponding to poinudte being kammererite, occur- 

 ring in the Urals, and at the well known locality of Texas, 

 Pa. It has been proved to be uniaxial by Descloizeaux "^ 

 and J. P. Cook, Jr.t Various authors have also designa- 

 ted it as rhodophyllite, chromchlorite, rhodochrom. The 

 chromiferous variety of dinochlore kotschuheile, from the 

 Urals, has been described by N. v. Leuchtenberg, ^ but 

 has since then, as far as I am aware, not been noticed from 

 any other part of the world, and its occurrence in Califor- 

 nia is therefore not without interest. 



V. Leuchtenberg arrives at the conclusion that kotscJiu- 

 heite is a variety of dinochlore, but differing from it in the 



*Miueralogie. T. I. 



t Am J. Sc. II. XLIV, p. 201. 



I Bull. Soc. Imp. de St. Petersburg. XIII, 34. 1869. 



