20 



PROCEEDINGS OF THE NATIOITAL MUSEUM 

 Measurement of vesuvianite, Figure 6 



VOL. 71 



The crystals vary gradually through elongation of the prismatic 

 direction to the proportions of Figure 7. Many crystals of such 

 proportions are very simple and the one illustrated is about the most 

 highly modified seen. This, upon measurement on the 2-circle 

 goniometer gave the following angles : 



Measurements of vesuvianite, Figure 7 



Other specimens show crystals, differing from the last chiefly 

 in greater opacity and darker green color, forming solid crusts so 

 that no individual is completely developed. These show some forms 

 not present on the more perfect crystals as illustrated in the drawing, 

 Figure 9. This crystal gave the following angles : 



Measurements of vesuvianite. Figure 9 



