340 University of California Publications in Geology [Vol. 10 



only an occasional broad face of the dodecahedron. Good crystals also 

 occur and some of the rhombic dodecahedrons measure ten centi- 

 meters in diameter. All of those collected are simple dodecahedrons 

 without other forms. Some of the crystals are mere shells of garnet 

 enclosing a center of white calcite. 



The massive grossularite was analyzed by J. B. Wright with the 

 following result : 



SiO, 



35.53% 



A1 2 3 



21.11 



Fe 2 3 



3.95 



FeO 



0.60 



CuO 



0.70 



CaO 



36.06 



MgO 



0.78 



Na.O 



0.20 



H 2 



1.23 





100.15 



G = 3.39 



Granular yellow garnet and dark brown massive varieties also 

 occur, apparently in connection with the pegmatite dikes. No analyses 

 of them have been made to determine the particular species. 



Diopside. — Associated with garnet in the zone of metamorphic lime 

 silicates, a deep green massive pyroxene occurs, which is probably a 

 diopside of a darker color than the crystals scattered through the 

 calcite. All of the crystals are of a pale yellowish green color and 

 occur as single crystals imbedded in the blue calcite. Most of them 

 are small, only a few millimeters long, but some have been found four 

 centimeters in length. They are all of one general type : short prisms 

 tapering off by a succession of unit pyramids to pointed ends, with or 

 without small basal planes. Figures 9 and 10, plate 24, show this 

 general habit and some of the combinations. The observed forms are : 



c (001) e (011 j X (331) d (131) 



a (100) z (021) o (221) M (121) 



b (010) v (221) * (Til) t (211) 



m (110) u (111) t (T12) e (T21) 



tt (231) new 



The new form truncates the edge (110) (121) and occurs on several 

 crystals. The edges have manj' rounded faces and some of the symbols 

 corresponding to them are given unlettered in the following table of 

 measurements and calculations. They are doubtful forms. 



