332 eakle: xanthophyllite in limestone 



essential to an adequate solution. The study of crystals from 

 the viewpoint of crystal forces is an integral part of geophysical 

 and geochemical research. 



MINERALOGY. — Xanthophyllite in crystalline limestone. Ar- 

 thur S. Eakle, University of California, Berkeley, Cali- 

 fornia. (Communicated by Edson S. Bastin.) 



The rare brittle mica xanthophyllite has not been reported 

 from any localities other than those in the district of Slatoust 

 in the Ural Mountains, where it, and its variety waluewite, were 

 found. 



The xanthophyllite described and named by Gustav Rose 1 

 was a wax-yellow mineral in scales and plates, occurring as a 

 constituent of a talc-schist in the Shiskimskaya Mountains, in 

 the Urals, and this yellow color was probably exceptional. 



Many years later the green variety was found, and named 

 waluewite by Kohscharof. 2 The waluewite occurred as a con- 

 stituent of chlorite schist in the Nicolai-Maximilian Mine, near 

 Slatoust. Small veins of calcite which occurred in the schist 

 also contained flakes of the mineral, merely as inclusions, how- 

 ever. The original yellow xanthophyllite and green waluewite 

 were schist minerals; so it may be of value to note the occurrence 

 of the green waluewite in another locality, and as a contact 

 metamorphic mineral in crystalline limestone, in association with 

 monticellite. 



The isolated hill of crystalline limestone and granodiorite 

 situated at Crestmore, about eight miles west of Riverside, Cali- 

 fornia, is one of the best studies in contact metamorphism that 

 exists anywhere, and upwards of fifty mineral species, among 

 them the recently described new mineral, wilkeite, 3 have been 

 found in the same quarry. The white marbleized limestone 

 rests as a capping upon a base of granodiorite, and the general 

 metamorphism of the original limestone beds has probably been 



1 Pogg. Ann. d. Phys. u. Chem. 50: 654. 1840. Also in his "Reise nach dem 

 Ural," 2: 120, 514, 527. 1842. 



2 Zeits. fur Kryst. 2: 51. 1877. Also in his Mineral d. Russ. 7: 346. 



3 Eakle, A. S., and Rogers, A. F. Amer. Jour. Sci. 39: 262. 1914. 



