334 



eakle: xanthophyllite in limestone 



wide band of massive monticellite, indicating that it was an 

 abundant mineral. The color is pale brown and luster somewhat 

 greasy. There are no crystal faces visible. The analysis gave: 

 Si0 2 , 36.02; FeO, 2.82; CaO, 34.36; MgO, 24.74; Ign., 1.25; 

 total, 99.19. 



TABLE I 

 Analyses of Waltjewite from Crestmore and Slatoust 



1. Average composition of waluewite from Crestmore, California. Sp. gr. 

 3.081. 



2. Analysis by Nikolajen of waluewite from Nikolai-Maximilian Mine, Dis- 

 trict of Slatoust, Urals. Zeit. fiir Krys. 9: 579. (Abstract). 



3. Analysis by Clarke and Schneider of waluewite from Nikolai-Maximilian 

 Mine, District of Slatoust, Urals. Amer. Jour. Sci. 43: 379. 1892. 



The association of the two minerals is of particular interest, 

 because waluewite may be viewed as having the composition of 

 monticellite with the spinel and alumina hydrate molecules. In 

 the discussion by Clarke and Schneider of the constitution of 

 the members of the clintonite group it was suggested that walue- 

 wite may have the monticellite molecule in addition to its spinel 

 and olivine molecules, although no direct association of the two 

 was then known. 



The two Crestmore minerals are products of hydrothermal 

 metamorphism of the limestone, and the waluewite has crystal- 

 lized in a lime carbonate solution in which the monticellite mole- 

 cule was the predominating component of the silicate mixture 



