j6 the nature of LOUISITE WALKER 



When these two portions were examined with the microscope, 

 it was found that the lighter was almost entirely free from quartz 

 spherules and had a density of 2.369 which agrees with the 

 known values for apophyllite. In the heavier portion nearly 

 all the grains were complex, consisting of radiating masses of 

 quartz usually attached to fragments of apophyllite. The 

 density of the heavier portion was found to be 2.542 which 

 would correspond to a mixture of quartz and apophyllite in the 

 ratio of 2 : 1. 



Fig. 1. Microphotograph of louisite spherules of quarts in apophyllite^ 

 crossed nicols x 40 diameters. 



