236 Emerson — Corundum and a Graphitic Essonite. 



The cyanite is in rather square blades with good cleavage 

 and basal parting and around its borders has broken up into an 

 alteration product. 



The whole field is filled with coaly matter in trains, aggre- 

 gates and groups of round balls which often occupy the center 

 of the corundum grains. This carbonaceous matter has plainly 

 been introduced in an oily or tarry condition and has been 

 inspissated in place, and the abundant graphitic matter in the 

 garnet gives indication of the same origin. 

 Amherst College, Amherst, Mass. 



